Virginia Gov. Robert McDonnell amended more than 100 bills approved by the General Assembly this year, making it slightly easier to vote on Election Day and allowing localities to spread the cost of new pension regulations over years, among other changes.

McDonnell vetoed an unprecedented seven bills but signed hundreds of measures, including one that would permit faith-based adoption agencies to deny placements that conflict with religious or moral beliefs and another that narrowly alters his transportation plan, although not to add significant new funding for roads.

The General Assembly will return to Richmond on April 18 to consider McDonnell’s action on the legislation, except on the two-year, $85 billion state budget, which lawmakers have not passed. It was unclear whether the legislature has the votes to override any of the vetoes.

As of the midnight Monday deadline, McDonnell had signed 733 bills and proposed amending 130 bills. One of his vetoes sidelined a popular measure that would have directed the Virginia Department of Education to develop uniform guidelines for physical education in public schools. McDonnell said the legislation was an unfunded mandate on localities and killed it for a second year in a row.

“It seems that Governor McDonnell will stop at nothing to ensure that Virginia’s children grow obese and develop life-threatening and expensive health problems,” Sen. Ralph S. Northam (D-Norfolk), a doctor who introduced the measure.

Staff members for the governor and the legislature said McDonnell (R) worked through the legislation until the last minute. McDonnell — who was traveling Tuesday on a four-day trade mission to New York and Canada — released a list of amendments and vetoes Tuesday afternoon as state workers updated Virginia’s online system.

Del. Robert G. Marshall (R-Prince William) said McDonnell’s office called him Monday at 11 p.m. to talk about a bill he sponsored that would ban state employees — including the Virginia National Guard and State Police — from assisting in the federal detention of U.S. citizens without criminal charges or court hearings. They agreed to tweak the language to say no state employee can “knowingly” participate in the indefinite detention of a citizen.

Local officials raised concerns about costs associated with pension changes after lawmakers passed a bill requiring local governments to give their employees a 5 percent raise to offset workers’ new 5 percent contribution into the retirement system. Localities said they would have to pay thousands and, in some cases millions, of dollars to pick up the costs associated with the legislation. (Currently, governments pick up the whole tab.)

For example, Prince William County, the state’s second-largest jurisdiction, estimates that the changes would cost $5 million, said Corey A. Stewart (R-At Large), chairman of the Board of County Supervisors. McDonnell’s decision to amend the bill allows county officials to spread the cost over five years.

“We’re completely satisfied with that,” Stewart said of the governor’s change. “We’re relieved.”

The governor also changed a pair of voter ID bills to authorize a signature-comparison requirement so that a voter without a valid ID may skip the proposed new step of going to the registrar to present identification, although that option will still exist. At least 12 other states have adopted signature provisions.

McDonnell also extended the amount of time in which a voter may send or present ID to a local election board; eliminated the provision that allows for voter ID requirements to be waived if an election official recognizes the voter; and sanctioned community college identification cards as acceptable forms of ID.

“Ensuring the security, fairness and openness of our elections are cornerstones of a strong democracy,’’ McDonnell said. “For people to have faith in their government, they must have faith in their elections.”

Sen. Stephen H. Martin (R-Chesterfield), who introduced the bill, said he will probably support the changes, although he preferred his stricter version.

Proponents argue that the identification bill is designed to prevent voter fraud. Critics say it would make it more difficult to vote.

McDonnell made some technical amendments to two of his education bills, including one to give tax credits to those who donate private- and parochial-school tuition to students, which Democrats warned would undermine public education.

McDonnell already had signed some bills, including those requiring that information about breast density be sent to women along with mammogram results; providing insurance coverage for families with autistic children ages 2 to 6; and requiring women to undergo ultrasounds before they have abortions.