In 1790, a ten mile square on the Potomac River was carved out to become The City of Washington in the Territory of Columbia; Pierre 1'Enfant drew up plans for the new city; and the government purchased the land that made up the city from its owners. The parcel of land we know today as Lafayette Square belonged to Edward Pearce, who had a farmhouse, orchards, and family graveyard here. After this land was bought. by the government, it became the front lawn of the President's Mansion and was called the President's Park. The Park was covered with workmen's shacks and building supplies during the construction of the White House, and when the lame-duck President Adams moved into the unfinished house.

President Jefferson, thinking such a large expanse of lawn too grand, too regal for the house of the president of a republic, had four blocks of Pennsylvania Avenue cut through, separating the Park from the White House. The President's Park was used as a commons until the War of 1812, when federal soldiers charged with protecting the White House used the Park as a campground. (Remember, the British burned the White House in 1824.) After the War, development of the Park began in earnest - the cornerstone of St. John' s Church was laid in 1816; construction of Decatur House (the first private residence here) began in 1828; and by the late 1820's nearly a dozen grand houses faced the Park.

The Marquis de Lafayette visited Washington in 1824; at that time, the President's Park became informally known as Lafayette Square. The name was formally changed to honor the hero on his death in 1834.

During the Civil War, the Square was again used as a military campground. President Lincoln is said to have frequently visited the troops guarding the White House. After the War, President Grant improved the Square - the land was drained and landscaped, and Grant installed his private zoo of prairie dogs and deer. Neighbors complained on the animals' noise, so the zoo was closed.

1900 marked the centennial of the "Removal of the Government", the government's move from Philadelphia to Washington, D.C. A Senate Commission directed by Senator James Macmillan including architect Daniel Root, landscape architect Frederick Law Olmstead, and artist Augustus St. Gaudens among its members, designed a new plan for the city. In the taste of the City Beautiful movement, Washington was to be redeveloped with a logical landscape, rebuilt with Classical Revival style buildings, and Lafayette Square was to be surrounded by office buildings like the Chamber of Commerce building. Congress approved the plan in concept, but not funds for its implementation.

Today's Square was designed by John Carl Warneke in the 1960's, who preserved historic buildings and interspersed non-intrusive modern office buildings. St. John's Church was designed by Latrobe as a Greek cross with a dome, and featured wood burning stoves by the cupola pillars for the congregation.