Collection consists primarily of architectural drawings of Richard Upjohn, his son Richard Michell Upjohn, and their partnership, known first as Upjohn and Company, and later as Richard Upjohn and Company. Among the numerous projects, chiefly residential and ecclesiastical, represented are Trinity Church in New York City (designed by Richard Upjohn and completed in 1846); the Connecticut State Capitol building in Hartford (designed by Richard Michell Upjohn), circa 1830-1903; designs for the Boston Custom House, undated; Grace Church in Providence, R.I., circa 1845; St. Paul's Church in Brookline, Mass., 1848-1852; St. Paul's Church in Buffalo, N.Y., circa 1850; the Central Congregational Church in Boston, circa 1850; St. Peter's Church in Geneva, N.Y., circa 1850s-1860s; the William Spencer House in Yellowhook, N.Y., 1853-1855; the E.B. Litchfield House in Brooklyn, N.Y., 1853-1855; Hamilton Hoppin House, Newport, R.I., 1856; Hobart College in Geneva, N.Y., 1858-1862; various structures for Green-Wood Cemetery in Brooklyn, N.Y., 1859-1863; St. James's Church in Brooklyn, N.Y., circa 1860s-1870s; the original St. Thomas's Church on Fifth Avenue in New York City, circa 1870 (the church was destroyed by fire in 1905 and replaced by Bertram Goodhue's existing church in 1913); and several plates from Richard Upjohn's book RURAL ARCHITECTURE. Account books, circa 1827-1910, recording both personal and business accounts; and a diary, 1829, recording Richard Upjohn's journey by ship from England to the United States.
Also, minutes kept by Richard Michell Upjohn for the American Institute of Architects, New York Chapter, Committee for Library and Publications, 1868-1877, and Executive Committee, 1867-1889; sketchbooks, 1850s-1870s; photographs of Upjohn buildings and portraits of Richard Upjohn; correspondence, wills, memorial tributes, manuscripts, printed material, and miscellaneous personal and business documents; and several drawings by other architects including Alexander Jackson Davis, Hobart Brown Upjohn, and Calvert Vaux