Heins & LaFarge provided the architecture and details for the Interborough Rapid Transit Company, the first precursor to the New York City Subway.
Some of the Cathedral trustees did not care for the original Romanesque-Byzantine design, preferring something more purely Gothic, and consequently they removed the project from LaFarge, the surviving architect of the team.
The rusticated masonry façade with a sparing use of Venetian Gothic and Richardsonian Romanesque details and the square corner bell tower with a crenellated parapet embellished with gargoyle gutter-spouts reveal Richardson's training.
An exercise in a somewhat subdued Richardsonian manner, in the Bedford-Stuyvesant section of Brooklyn, is Heins & LaFarge's Reformed Episcopal Church of the Reconciliation (1890), now the Most Worshipful Enoch Grand Lodge of the Order of Masons.
[6] Roosevelt was also a prime mover behind the creation of the New York Zoological Society, for whom the partners designed the original nucleus of buildings (1899–1910, now called the Astor Court) as a series of pavilions symmetrically grouped round the large sea lion pool, all in a sturdy brick and limestone Roman Ionic and Doric, with the heads of elephants and rhinos, lions and zebras projecting festively from panels and friezes.
At Yale University, their rusticated Richardsonian Romanesque design for a chapter building of St. Anthony Hall, also known as the Delta Psi fraternity, stood from 1894 to 1913.
Also in 1899, at the United States Military Academy, West Point, they erected the Roman Catholic chapel of the Most Holy Trinity, also hearkening back to their Richardson apprenticeship with an essay in rusticated granite, with a battlemented corner tower and a heavy arcaded porch.
When the Interborough Rapid Transit's original line opened on October 27, 1904, its showpiece station was City Hall, designed by Heins & LaFarge using uninterrupted sweeping Guastavino-tiled arches and vaults which incorporated shaped skylights and mosaics and polychrome terracotta panels.
After Heins died in 1907, LaFarge decided to pursue a solo practice and in 1908 was replaced as architect in charge of the IRT project by Squire J.
The firm sent two young architects, W. Marbury Somervell and Joseph S. Coté, to oversee construction on the site, who went on to establish a thriving architectural practice in Seattle.