The building in which the Supreme Court sat from 1791 on was erected by the City of Philadelphia to accommodate the growth of municipal departments and functions. During the Colonial period the city government occupied the small courthouse at Second and High (now Market) Streets. When the Federal Government came to Philadelphia, the new building was not yet completed, and the Supreme Court of the United States met first in the Pennsylvania Supreme Court Chamber in the State House. After August 1, 1791, the Supreme Court generally occupied the Mayor’s Court, the large room at the south end of the first floor, in the new City Hall. It is possible that the corresponding room on the second floor was also used on occasions by the high tribunal. During its occupancy of the building, the Supreme Court was first presided over by John Jay, who was succeeded in turn as Chief Justice by John Rutledge and Oliver Ellsworth. Here the court began its active work, thereby laying the foundation for the development of the Judicial Branch of the Federal Government. [Illustration: _First Bank of the United States, built in 1795._ Engraving by Fenner Sears after C. Burton, 1831. Courtesy Philadelphia Free Library.] The ground on which Congress Hall stands was purchased for the Province of Pennsylvania in 1736. Although there had been plans for a long time to erect a courthouse on the lot, it was not until 1785 that the Assembly of Pennsylvania passed an act to appropriate funds for the erection of the building. Work began in 1787 and was completed in 1789. This county court building became the meeting place of the first United States Congress, Third Session, on December 6, 1790. Frederick Augustus Muhlenberg was then Speaker of the House and John Adams, President of the Senate. It is today the oldest building standing in which the Congress of the United States has met. [Illustration: _Alexander Hamilton, Secretary of the Treasury in Washington’s administration, whose comprehensive program placed the new Nation on a firm financial basis._ Painting by Charles Willson Peale (c. 1791). Independence Hall collection.] Before the courthouse could be turned over to the United States Congress, alterations had to be made to fit the building for its new purpose. The first-floor chamber, to be used by the House of Representatives, was furnished with mahogany tables and elbow chairs, carpeting, stoves, and venetian blinds—all of fine workmanship. In addition, a gallery was constructed to hold about 300 people. The Senate Chamber on the second floor was even more elegantly furnished. Then, between 1793 and 1795, to accommodate the increase in membership of the House from 68 to 106, the building had to be enlarged by an addition of about 26 feet to the end of the original structure. In 1795, a gallery was constructed for the Senate Chamber similar to, although smaller than, the one on the floor below.