John Mervin Carrere was born in Rio de Janeiro, Brazil, the son of a prosperous French-American coffee trader. He graduated in 1882 from a course of studies at the Ecole des Beaux- Arts, Paris, where he had met Tom Hastings through a student design project. The two men became even faster friends when they both worked as draughtsmen for the great architectural firm of McKim, Mead and White, before striking out on their own in 1885. Carrère married Marion Dell of Jacksonville, Florida, in 1886
Carrere's life was cut short dramatically by a collision between the taxi in which he was riding and a streetcar. He suffered a brain concussion and never regained consciousness.
Thomas Hastings was a New Yorker from a colonial Yankee background; his father was a Presbyterian minister and president of the Union Theological Seminary. His grandfather had composed hymns, notably 'Rock of Ages.' Hastings abandoned his college preparation courses to work with the chief designer at Herter Brothers, the premier New York furnishers and decorators. He married Helen Benedict of Greenwich, Connecticut.
Carrère was an active member of the American Institute of Architects, a founding member of the Beaux-Arts Society of Architects. The admirable Carrère was outspoken and frank. Hastings noted his "seriousness and absolute fearlessness in speaking the truth under all conditions and at all times." Carrère was the one who spoke flawless French. Hastings was the genial partner who enjoyed excellent social connections, a prerequisite for an architect of that generation. Hastings was the articulate writer and publicist of their work.
Their first major commissions came from a parishioner of Rev. Hastings, Henry Flagler, the Florida developer, for whom the partners built the Ponce de Leon Hotel (1885 - 1888) in St. Augustine, Florida, and followed it with a succession of St. Augustine hotels and churches.
After Carrère's death in 1911, Tom Hastings went on to design the Arlington Cemetery Tomb of the Unknowns and Henry Clay Frick's Louis XVI mansion on Fifth Avenue, now the Frick Collection, as well as residences for such distinguished names as Guggenheim, duPont, Harriman, even a 'poultry cottage' for William K. Vanderbilt. After World War I, Hastings designed the American Monument in Paris that memorializes the defeat of Germany at the Marne. Hastings outlived the Beaux-Arts world. Though he dressed up the Manhattan Bridge in a Beaux-Arts skin and helped clad conservative office buildings in Roman masonry, he denounced skyscrapers as "bad in style, definitely bad for city traffic and the health of the citizenry". He felt a zoning law should have been passed to limit their height to a maximum of eight stories as has been done successfuly in Paris.
The joint career of the firm lasted from 1885 to 1911, The early work of the firm was robust and dramatic, Baroque in flavor, with well-designed somewhat overscaled details, an inheritance of their Ecole des Beaux-Arts training. After the World Columbian Exposition of 1892, the firm's syle became more chaste and refined, The classicizing surfaces of their work never compromised the functionality of the interior spaces and circulation. They took advantage of new technology, from structural steel to electrification, even centralized vacuum-cleaning. Their masterpiece is the New York Public Library, begun in 1897 and opened a few weeks after Carrere's tragic death. The firm rebuilt the East Front of the U.S. Capitol building, 1904, and the House and Senate Office Buildings in Washington DC.