At the time of the building's commission, the society was at its maximum political popularity with members such as U.S. senator Robert F. Wagner, governor Al Smith, and mayor Jimmy Walker.

However, after Tammany Hall lost its influence in the 1930s, the building was sold to an affiliate of the International Ladies' Garment Workers' Union in 1943.

The renovation preserved the facade while totally gutting the interior, and a glass domed roof was added to honor Chief Tamanend, namesake of the Tammany Society.

The particular neo-Georgian features in the Tammany Hall Building include Flemish bond brickwork; rectangular windows with stone keystones, set in arched openings; and wrought-iron balconies.

The bracketed gable, on the pediment above the portico, is not of neo-Georgian design but was likely inspired by a niche on the facade of the 14th Street building.

[1] The exterior design features are evocative of government buildings in the American colonial and Federal styles that were built in the later 19th century, when the society was founded.

These features include a first level above a raised basement; a portico on Union Square East, with a pediment supported by columns in the Doric order; a hip roof; and a frieze running along the top of the structure.

According to a commemorative publication from the Tammany Society, these features were inspired by the design of Federal Hall in Lower Manhattan, as well as by Somerset House in London.

[7] In the round-arched gable of the pediment, above the portico, there is a panel depicting arrows intertwined with an olive branch, which flank Tammany Hall's circular logo.

[11][9] The glass domed roof, reminiscent of the rising turtle shell from the Lenape creation story, was added during the 2016–2020 renovation to honor Chief Tamanend, namesake of the Tammany Society.

[18]: 9  The organization—named after Tamanend, the chief of the Lenape who originally occupied New York City—extensively used Native American titles and terminology, for instance referring to their headquarters as a wigwam.

[20][21] After the expansion of the Consolidated Gas building was announced in 1926,[18]: 9  the old Tammany Hall "wigwam" was sold to J. Clarence Davis and Joseph P. Day, of real estate syndicate D&D Company, on December 6, 1927.

[28] In January 1928, a month after the purchase of the site, Charles B. Meyers was selected along with Thompson, Holmes & Converse as the building's architects.

[10][34] Construction progressed quickly, without any cornerstone-laying ceremony to mark the start of work, and by December much of the structure was substantially complete.

[44][45] Tammany's leaders moved to the National Democratic Club on Madison Avenue at East 33rd Street, and the Society's collection of memorabilia went into a warehouse in the Bronx.

[40] The ILGWU enlarged the stage and furnished the offices, officially rededicating the building on December 18, 1943, at an event with several leaders including mayors La Guardia and Jimmy Walker.

[44][47] After completing a renovation of the former Tammany building, the ILGWU opened meeting spaces, offices, art studios, and classrooms there.

[56] In 1969, the auditorium was also the location of a high-profile disagreement between two Central Labor Council leaders, who endorsed opposing candidates in the 1969 New York City mayoral election.

[58] At a premiere event for Harold Pinter's play Old Times, ILGWU executive vice president Wilbur Daniels had a chance encounter with Gene Feist, co-founder of Roundabout Theatre Company.

[61] 44 Union Square was then leased in June 1994 by Alan Schuster and Mitchell Maxwell, who also operated the Minetta Lane Theatre in Greenwich Village.

[7][62] In preparation for converting the space for use as the Union Square Theatre, Schuster and Maxwell renovated the interior, painting the dome a sky-blue hue, and replacing the seats' upholstery with burgundy materials.

[62] The building started housing the New York Film Academy in July 1994,[7][63] and the Union Square Theatre held its first performance in the space that November.

[68] Prior to the 2016 reconstruction, the owners consulted and received approval from the New York City Lenape Center regarding use of the creation story imagery that inspired the dome design.

[78][79] Early architectural critics lauded the Tammany Hall Building as a paragon of the neo-Georgian style in New York City.

[4] The Real Estate Record & Guide said that the "severe Colonial columns" placed at the center of both facades contributed to the building's "dignified architectural treatment".

[81] George Shepard Chappell, writing in The New Yorker under the pseudonym "T-Square", praised the Tammany Hall Building's "exceptionally charming design", saying that it was a "real adornment" to Union Square.