After a day-long struggle, Congress passed a $16.9 billion emergency supplemental appropriation bill last night and left town for a 2 1/2-week recess.

The long break is to let Republicans attend their presidential nominating convention. Democrats can go home and tell voters how they bravely bit the bullet last spring to contruct a balanced budget for next year and then, when frightened by GOP tax-cut efforts, spit it out and promised a tax cut. Together with the revenue loss from recession, the cut probably means the end of the balanced budget.

The Senate yesterday passed a $51 billion military procurement authorization bill, $5 billion above the president's request, and the House discussed but did not complete action on a railroad deregulation bill.

But the center of attention was the big money bill needed to carry the government through the final three months of the fiscal year. House-Senate conferees had worked until 2:30 a.m. yesterday in an effort to reach agreement on 344 Senate amendments to the House bill. They were able to agree on everything except the Senate effort to attach a long-stuck 1980 foreign aid appropriation bill to the emergency supplemental, and left that decision to a vote by both bodies.

The House promptly approved a foreign aid compromise that split the difference with the Senate, adding half a billion dollars to the spending level the program had been limited to because its regular appropriation bill for the year three-fourths gone hasn't passed. This was first approved by a vote of 198 to 196 -- which was acheved by some arm-twisting by Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) after the roll call ended -- and then ratified, 212 to 178.

But the House then discovered that the conferees had cut out $143 million in revenue sharing to which the states are legally entitled. After two hours of 'angry wrangling, the House repealed the half billion dollars it had just voted for foreign aid and voted instead, 222 to 140, to include $126 million for foreign aid and restore the revenue-sharing funds. It then sent the bill to the Senate to approve or reject the House action.

The foreign aid funds approved include the $75 million in post-civil war economic aid to Nicaragua that President Carter has been trying to get from Congress since last year.

The foreign aid money bill was held up for months by a dispute over the level of U.S. contributions to international development banks and on conditions on use of American funds. When that was straightened out last February, the bill was held up until the congressional budget resolution was passed providing needed additional spending authority.

The conferees agreed to restore most of the bonus authorized for super civil servants in the senior executive service, funds which the House had squeezed down to almost nothing. The conference agreement would permit payment this year of the full bonus of $10,000, and more in a few cases, to 25 percent of the 7,000 employes in this new category. It had never been planned to give the bonus to more than 35 percent.

The supplemental had been held up for several weeks because Congress had to adopt the first budget resolution making room for more spending in this fiscal year. During the delay several programs ran out of funds or came perilously close to it.

The bill contains $343 million in black lung payments, $446 million for food stamps, $951 million to repair damage caused by the eruption of Mount St. Helens, $870 million for other disaster relief, $1.5 billion for jobless benefits for workers thrown out of a job by imports, $200 billion for refugee assistance, and several billion for pay raises.

The Senate had voted several large increases above the House bill, such as adding $1.5 billion to become available immediately to repay Chrysler Corp. loans if the ailing automaker cannot.To cover the spending increases, the conferees made several cuts, including rescission of $2 billion previously appropriated to build up the nation's strategic petroleum reserve -- even though Congress told President Carter in a bill enacted this week to get going and build up the reserve for emergency needs.

The record of major congressional achievement after nearly six months isn't very long, but some new ground has ben plowed and some other new ideas are moving though the legislative pipeline.

After weeks of effort, Congress passed a balanced budget resolution, though that goal will probably not be achieved unless there is a quick and marked inprovement in the economy. Also for the first time since it has been shaping a comprehensive budget, Congress agreed to submit to the discipline of reconciliation, cutting spending to stay within its targets.

Three of the major energy bills Carter sent Congress last year to help reduce reliance on foreign oil made their way through House-Senate conferences and two have become law -- a tax on the profits from decontrolled domestic crude oil and a measure creating a $20 billion fund to encourage production of alternative energy sources. A third bill to cut red tape in the way of new energy production programs was sent back to conference, for fear it would trample on state laws, but may be rescued later in the year.

Carter's bill to register 19- and 20-year olds for a possible military draft passed after protracted debate over whether it was a step toward stronger national security or a meaningless gesture. Despite the effort to balance the budget, both House and Senate passed military procurement authorization bills about $5 billion higher than Carter requested.

Last year's airline deregulation law has been followed by trucking deregulation. Railroad deregulation is expected to become law soon. Congress also enacted a major banking overhaul bill which will remove interest ceilings on savings accounts and permit payment of interest on checking accounts.

When it returns, Congress will have to pass all 13 appropriation bills which make up the budget for the fiscal year beginning Oct. 1. It also must approve a final budget resolution setting binding spending ceilings.

A bill adding tough enforcement provisions to a 1968 law forbidding racial discrimination in housing has passed the House. It has been delayed in the Senate Judiciary Committee, but a Senate vote is promised. Legislation creating a new fund to dispose of hazardous chemical wastes, partly financed by industry, has moved through committee in both houses.

The Senate has agreed to take up after the recess a measure deciding the use of Alaska lands, which has been called the environmental bill of the century, but it will have a tough race against the clock.

Congress still has to take final action on a number of program extensions which appear certain to pass, such as higher education, housing and community development and mass transit. The recession is giving a push to other bills providing training and jobs are for unemployed teen-agers, a public works program and extension of revenue sharing to local governments and perhaps states.

Then there are several bills which are moving but which have been around before and didn't make it, and may not again -- such as lobby disclosure and sunset legislation to kill programs that are not reauthorized periodically. a

Also still ahead of Congress is a decision on when to move a tax-cut bill and how much to give taxpayers before or after election day.