Built between 1832 and 1834, the Merchants' Exchange Building, also known as the Philadelphia Exchange, is located on the triangular site bounded by Dock Street, Third Street, and Walnut Street. This monumental office building was designed by William Strickland and is an exquisite expression of the Greek Revival style, the first national American architectural style. The ideals of Greek democracy were attractive to citizens of the American Republic and provided the best model for American architects to emulate as a national style.
The building is also significant to nineteenth century Philadelphia because it served as a commercial and financial center as well as the site of a post office. Previously, meetings between merchants took place in small coffee houses or taverns located near the Delaware riverfront. By 1831, it was believed that a central location was required to carry out business transactions and negotiations. Located on the Dock Street side of the building, the United States Post Office occupied a large room and was the first in the country to sell stamps