Because of an editing error, an article yesterday about Congress' commemorative session in honor of the Constitution said that the congressional delegation left Washington for Philadelphia in early afternoon. The congressional train departed at about 9:40 a.m. (Published 7/18/87)

PHILADELPHIA, JULY 16 -- Independence Hall, where the Founding Fathers spent the summer of 1787 writing the U.S. Constitution, again echoed with impassioned rhetoric today as members of the current Congress assembled here to celebrate two centuries of constitutional government.

More than 200 senators and representatives joined Philadelphia in commemorating the Great Compromise -- the creation of a bicameral legislature. That breakthrough ended the stalemate between populous and sparsely populated states, enabling the Constitutional Convention to forge an American republic.

"Because of that compromise, and others that flowed from it," said House Speaker Jim Wright (D-Tex.), "13 weak, endangered little republics were able to bind themselves together and survive as one strong nation -- ultimately to become the strongest nation on earth."

At a time when the Iran-contra hearings are probing whether the executive branch has overstepped its constitutional bounds, delegates to today's special session affirmed their faith in the document's self-protecting mechanisms.

Senate Majority Leader Robert C. Byrd of West Virginia urged Congress to resist "habits of power that are inherently undemocratic and unconstitutional."

"We are continually amazed by the failings of those in power who, in defense of democracy, ignore its most basic and fundamental tenets," Byrd said. "It is clear that a policy without checks and balances is a policy that too often loses its way," he added.

The observance was one of a series to occur throughout the country this year. The guests of honor took a chartered train to Philadelphia from Capitol Hill, shortly after the Iran-contra hearings recessed at about 12:45 p.m.

The thousands who gathered in front of Independence Hall witnessed a colorful clash of eras. Old bells pealed and the rumble of overhead fighter jets punctuated the opening ceremonies, while a town crier in colonial garb announced the presence of legislators.

Fifty-five pre-selected senators and representatives, including the Democratic and Republican leadership of the Senate and the House, filed into the historic chamber.

Rep. Lindy Boggs (D-La.), one of the chief planners of the bicentennial festivities, was unanimously elected president of the delegation. She took her place in a replica of the chair from which George Washington surveyed his colleagues as they worked.

A resolution adopted by today's assembly paid tribute to the compromise -- approved by one vote on July 16, 1787 -- which provided for equal representation of all states in the Senate, but representation based on population in the House.

Members of the congressional leadership praised the constitution's delicate balance of powers and its protection of individual liberties. There were repeated reminders of its imperfections and resilience and of America's progress since 1787 when the framers decided against abolishing slavery.

"You know, in 1787, I wasn't part of the Constitution," Rep. William H. Gray (D-Pa.), who is black, said in welcoming remarks. "But because the framers knew the inevitability of justice and because they built a framework that allows it, this nation has made such progress."

After the official gathering in Independence Hall, representatives of the two Houses convened separately in nearby Congressional Hall, where Congress met from 1790 to 1800.

The patriotic public display stood in contrast to the original deliberations, which took place in strict secrecy.

The congressional visit to Philadelphia continues through the weekend, as legislators and their families attend a variety of events organized by local officials and the Chamber of Commerce.

A number of groups, most of them protesting U.S. policies in Central America, demonstrated near Independence Park.

Another group, the Philadelphia Lesbian and Gay Task Force, which had fought an unsuccessful legal battle to demonstrate on park grounds during today's ceremonies, gathered to call for a gay bill of rights. None of the protestors attempted to disrupt the ceremony.