Grand Army Plaza in Brooklyn, New York is an 11-acre (4.4 hectare) oval plaza that forms the main entrance to Prospect Park in the borough of Brooklyn, New York City.. It was designed by Frederick Law Olmsted and Calvert Vaux in 1867. Originally known as Prospect Park Plaza, but renamed in 1926, it is perhaps best known for the Soldiers' and Sailors' Memorial Arch – a Beaux-Arts style triumphal arch dedicated "To the Defenders of the Union, 1861-1865."
The plaza’s main feature is the Soldiers’ and Sailors’ Memorial Arch The arch was constructed between 1889 and 1892. In August 1889, a blind jury of two experts, appointed by the Soldiers and Sailors Monument Commission, selected the design of John H. Duncan from a field of thirty six entries that had been submitted the previous year. Duncan, who would go on to design Grants Tomb in the following decade, proposed a free-standing memorial arch of a classical style similar to the Arc de Triomphe in Paris. After two and a half months of site preparation, William Tecumseh Sherman laid the cornerstone of the arch on October 30, 1889. After almost three years of construction, President Grover Cleveland presided over the unveiling on October 21, 1892.
Inside the arch and on facing walls are equestrian relief sculptures of Abraham Lincoln and Ulysses S. Grant. William Rudolf O'Donovan (1844-1920) sculpted both men and Thomas Eakins (1844-1916) did the two horses. The Arch gained its monumental statues nine years later. They were first suggested by the architectural firm of McKim, Mead and White as part of a plan to formalize the plaza in the spirit of the City Beautiful movement. Park Commissioner Frank Squire liked the proposal and in 1894 engaged Frederick MacMonnies to design three sculptural groupings for the Arch, the Quadriga, The Spirit of the Army, and The Spirit of the Navy.
The Quadriga resides at the top. It depicts the lady Columbia, an allegorical representation of the United States, riding in chariot drawn by two horses. Before her are two winged Victory figures, each leading a horse away from the quadriga, and each blowing a long trumpet. The removal of the horses is meant to symbolize their return to peacetime purposes, while the trumpets proclaim victory and emancipation. The lower pedestals facing the park hold two relief statues: one represents the Spirit of the Army group and the other the Spirit of the Navy. The work on the statues took nearly seven years to complete, about twice as long as the construction of the arch itself.
The arch was designated a national historical landmark in 1973, and the crowning sculpture was restored after the chariot's figure fell out in 1976.
To the right of the photo is Richard Meier’s 1 Grand Army Plaza apartment building, which was completed in 2009. The AIA Guide calls it "a massive beached whale."