Even though it has cut corners and could falter in the final stretch, the 97th Congress already has made history with a wrenching departure from a half-century of trying to advance social welfare through ever more government spending.

Despite some sham cuts and scare tactics, even the balkiest of the committee fiefdoms have -- at least on paper -- approached, met or exceeded the spending cuts that Congress ordered last month in response to President Reagan's call to arms against budget bloat.

Assuming Congress finishes the job by actually enacting program cuts approximating $35 billion, as it pledged to do, spending targets will still be higher next year than this year ($695.5 billion as opposed to $661.4 billion). But spending will be less than it otherwise would have been, and the thrust of government investment will shift sharply to national defense and away from the domestic programs that have their roots in the New Deal, New Frontier, Great Society and social activism of more recent years.

The drive behind the budget-cutting effort is the sense in Congress that Reagan is scoring high with the American people in pledging to cut government spending. The wisdom and humaneness of the cuts will be long debated, especially as the actual retrenchment begins to be felt. There is little backlash as yet, in part because few programs actually have been cut. "Pain" -- a word heard often among congressional Democrats these days -- is largely anticipatory.

To cushion the budget blows, some committees, especially in the Democratic-dominated House, have approved cuts more cosmetic than real, like putting a "cap" on food-stamp spending without cutting costs. They have also invited rebellion by proposing an end to the ever-popular impact aid program, closing up to 10,000 post offices, cutting Head Start programs and curtailing meals for the elderly. Escape hatches also have been provided, such as future congressional veto of the post office closings.

Citing these gambits and sensing their power, the administration and House Republicans are drafting a House substitute that would more precisely accommodate Reagan's program, as well as the cuts approved by the Republican-controlled Senate, including a modified version of Reagan's block grants to transfer more money and power to the states. A substitute would ease the potentially enormous problems of resolving differences in conference -- and, if it works, give Reagan another stunning victory, almost on the eve of his tax fight. But the votes would have to be there; a defeat could be devastating.

The cuts proposed by the 29 committees, 15 in the House and 14 in the Senate, will be packaged this week by the Budget committees of the two houses. Floor consideration is expected within a month. The target for completion is late July, although it may be difficult to meet.

So deep and complex are the cuts (a bill of 3,000 to 4,000 pages is possible) that it may take months to know the full implications. The cuts go far beyond numbers, virtually rewriting many programs. Here are some examples of the highlights, as known now: Food Stamps, Nutrition

About 1 million of the 22 million recipients of the nation's largest welfare program would lose their benefits -- and more would have theirs cut back -- under a reduction of roughly $1.5 billion in food-stamp spending approved by House and Senate Agriculture committees.

Both committees "cap" the program at $10.8 billion. But few believe the program will stay within the cap, even with the Senate's tighter eligibility guidelines. Some House conservatives are protesting that the proposal invites a possibly budget-busting supplemental appropriation later in the year.

At least $900 million would be cut from child-feeding programs, mostly from the school lunch program under which 12 million children get free or reduced-price lunches. The summer feeding program would be cut, along with the special milk program. The House would also cut "Meals on Wheels" for the elderly by 25 percent. Jobs

One of the biggest budget cuts of all comes from Comprehensive Employment and Training Act (CETA) programs, principally the oft-criticized public service jobs program. The Senate proposal would eliminate public service jobs entirely, saving $3.8 billion, while the House proposal cuts $2.8 billion.Both would wipe out the Young Adult Conservation Corps. Federal Worker's Pay

The Senate would follow Reagan's lead and provide a pay increase of 4.8 percent next year, while the House would allow 5.4 percent. Both are a far cry from the roughly 13 percent that would be allowed under the official comparability standard for keeping federal pay in line with private enterprise. The House would end "double-dipping" under which 181,000 military retirees take civilian jobs while getting military pensions; the Senate would not. However, the Senate would go from twice-a-year to once-a-year cost of living increases for federal pensions, while the House would not. Impact Aid

The House plan kills the popular, long-established school-aid program to help communities that are "impacted" with large numnbers of federal employes, which has been a boon to the Washington area. Every presidlent since Eisenhower has tried (and failed) to kill the progaram. The Senate proposal retained $200 million of the roughtly $800 million in impact aid, as Reagan wanted, restricting it to pay for children whose families both live and work on military bases. College Loans

The plans of both houses would make big cuts in the popular guaranteed loan program under which 3 million college students can borrow at low interest rates for their schooling. Both would impose an origination fee -- 5 percent in the Senate and 3 1/2 percent in the House -- for loans. The Senate would restrict loans when family income exceeds $25,000; the House plan would bar loans altoghether at that income level. Loans of up to $2,500 are now provided regardless of income. The House estimates its plan, which would save about $500 million, would eliminate as many as 1 million students, about a third, from the program. Also, interest rates for parental loans, a separate program, would be increased from 9 to 14 percent. Education

The House would cut the biggest program, giving aid for teaching the most disadvantaged children, to reflect rescissions for this year -- or by $410 million, leaving $3.1 billion for next year. The Senate would provide $3.3 billion. Both would directly or indirectly cut funds to help shcool districts desegregate.

The House plan rejects Reagan's proposal for combining education programs into block grants to the states, while the Senate waters it down drastically, in effect excluding $4.6 billion of $5.1 billion in education programs, such as aid to the poor and handicapped, from the block grant. Subsidized Housing

New and refurbished units of public and rent-subsidized housing would be kept to 176,000 under the House plan and 150,000 under the Senate plan -- a sharp reduction from the 260,000 units that the Carter administration proposed. Overall savings for the future: $12 billion to $17.8 billion. Unemployment Assistance

Committees in both houses eliminated, among other things, the so-called national trigger for extended benefits -- for total savings of up to $1.3 billion under the House plan (more under the Senate's plan). They also would save $1.3 billion by cutting trade adjustment assistance for workers idled by imports. Payments would be cut and limited to 26 weeks after regular unemployment aid runs out. Medicare, Medicade, Black Lung

The House proposal saves $1.6 billion (the Senate even more) from Medicare in a variety of ways, included added charges and higher deductibles. For Medicaid, Senate Finance proposed a "cap" on program growth of 9 percent, higher than Reagan's proposed 5 percent, but reduced the state-matching minimum from 50 to 40 percent, which will hurt the District of Columbia, Maryland and 11 other states. Democrats on House Commerce want $938 million in savings, with a complicated reduction plan instead of a cap.

The House, as Reagan wanted, would phase out Professional Standards Review Organizations, under which physicians review Medicare and related services with a view toward keeping down costs. The Senate proposal would retain PSROs.

For the $770 million program of black-lung benefits for coal miners, the House proposal calls for a special user fee on operators to help pay for benefits, while the Senate made no changes pending an overhaul proposal from the administration. Health

Regan got a large part of the money cuts he wanted in health services spending but fell far short on his plan for combining 25 health programs into two block grants. Committees in both houses agreed to a maternal and child health mini-grant, retaining some categorical requirements. The House Commerce health subcommittee rejected block grants, but the Senate Labor Committee adopted a modified approach that shields existing programs like neighborhood health centers and community mental health centers. Welfare

The House proposal cuts Aid to Families of Dependent Children and related programs by more than $800 million (the Senate even more). Both plans would allow, but not require, states to set up "workfare" programs to require work in exchange for aid. Reagan wanted mandatory "workfare." House Ways and Means gave Reagan many of the cuts he wanted, $3.2 billion in all, including phasing out student benefits and minimum benefits, delaying half the 1982 cost-of-living adjustment until Oct. 1 and eliminating lump-sum death benefits in some cases. Senate Finance approved similar cuts. Economic Development

Both the Applachian Regional Commission and Economic Development Administration would be ended in 1982. The Carter budget proposed nearly $1 billion for the agencies. In the Senate, 1981 money for the two agencies would be wiped out also, prompting threats of a fight on the floor because the Appropriations Committee approved the 1981 money. Water Projects, Clean-Up

Committees in both houses went along with Reagan's proposal for a $1.5 billion limit on water project spending, with the Senate proposing an obligational ceiling as well on the Corps of Engineers for the first time.

Regan recommened stripping out budget authority for water clean-up for next year, reforming the program and then resuming it at an annual level of $2.4 billion. The Senate would go along. The House cut $3.5 billion from a $3.6 billion total. Agriculture

In addition to food-stamp cuts, the biggest reduction appears to be in dairy price supports: about $500 million worth. A total of $2 billion more would be saved in 1983 and 1984.Also, fees would be charged for some previously free farmers' programs like warehouse inspections, and many other programs -- from home interest subsidies to water and sewer loans -- would be cut. Veterans Benefits

This politically popular program suffered relatively little. Most of the savings would come from putting restrictions on the $300 burial benefit for survivors of wartime veterans. The Senate also cut from one year to six months the time during which veterans can get free dental care after discharge. The House picked up minor savings by eliminating flight training and correspondence courses from the G.I. Bill of Rights. Maritime

Committees in both houses tucked their maritime authorization bills into the budget-cut package, throwing out construction subsidies but keeping operating subsidies. Because there will be no more construction subsidy, the House proposal would allow an American flag operator to buy his ship abroad and still be eligible for operating subsidies, which can't be done now. Foreign Aid

Committees were supposed to cut $250 million from bilateral aid, but had already sliced deeply into it in their authorization bills, leaving only $45 million for the House to cut. It made its savings from the Food for Peace program, but left it funded well above what Reagan wanted. The House proposal would provide $271 million of the $850 million requested by Reagan for the International Development Association, an arm of the World Bank, while Senate staffers say the Senate proposal makes no cuts in Reagan's IDA request. Legal Serivces Corp.

This 7-year-old program for providing legal services to the poor is one of the major agencies targeted for extinction by Reagan that may survive in Congress. The Senate proposal cuts spending by more than two-thirds to $100 million, while the House will short consider a LSC reauthorization bill that anticipates funding of $260 million. Energy, Fuel Assistance

Both houses will put "caps" on energy spending -- $5.9 billion for the Senate, $5.6 billion for the House -- that anticipate cuts in synthetic fuels demonstration projects, conservation, research and development and alcohol fuel development. Energy spending for the militay is untouched. Both proposals are roughly consistent with Reagan's in the energy area, although the Senate would restore some money for conservation and research. The House Science Committee purposes termination of the Clinch River breeder reactor, for which Reagan proposed increased spending. The Senate proposal would continue the Clinch River project.

The Strategic Petroleum Reserve is the wild card in the budget deck. Both the Senate Energy Committee and Democrats on the House Energy Committee assume nearly $4 billion worth of private financing to supply the reserve next year. If it has to be filled at taxpayer cost, the anticipated overall savings will be reduced by up to $4 billion.

For low-income fuel assistance, the House would provide $1.4 billion and the Senate $1.8 billion. Both plans loosen or eliminate federal controls, but reject Reagan's idea of combining fuel aid with welfare emergency aid into a block grant. Without cuts, the program is estimated to cost $2.2 billion next year. Postal Service

Both houses would cut nearly $1 billion in postal subsidies, with the House including a political bombshell -- and possible escape hatch -- in the form of a recommendation that $100 million of the savings come from closing or consolidating up to 10,000 of the country's smallest post offices. Some say this would be so unpopular that Congress would have to back off, which it would allow itself to do by providing that a shut-down plan drafted by the postmaster general could be vetoed by Congress. Transportation

Both Commerce committees approved $735 million for Amtrak rail passenger service: $122 million more than Reagan originally proposed and enough to keep 85 percent of the system intact, according to Amtrak President Alan Boyd, who previously estimated that Reagan's proposal would have allowed only service in the Northeast.

Conrail was cut, too, under a plan allowing for a transitional period before it is to be transfered to the private sector. Other cuts ranged from $1.3 billion from mass transit to a proposal from House Commerce Committee Democrats to end free lnches (literally) for the secretaries of transportation and commerce. Export-Import Bank

Both banking committees cut credit for U.S. exporters, the House ($2.4 billion) more deeply than the Senate ($1.3 billion). The House cut more heavily to keep more money for subsidized housing.