"A temple of humanity...a monument of mercy"
For a brief time after its founding, the Orphan House operated on the site of Trinity Church near Wall St. This was not the ideal location for an orphanage in the view of the Board members, so they purchased land belonging to the Society of the New York Hospital on the Morningside Plateau adjacent to the Bloomingdale Asylum (open since 1821). The 24.755 acres were situated between 109th and 113th St. Construction of the orphanage was delayed until 1838, because John Leake had forbidden the use of the capital to erect it. The main building's cornerstone was laid on 28th April 1838 . It was completed in 1843 and was opened for the reception of children on November 1st 1843. 
The name of the architect, Ithiel Town, remained unknown for years until it was discovered by Geoffrey Carter in 1990.  "The building, constructed of brick and designed in Ithiel Town’s favoured Greek Revival style," featured "austere Ionic temple fronts facing north and south."  The Greek Revival style was often associated with Christian values at the time of the asylum's establishment. It inspired Reverend Dr. Knox of the Dutch Church in his address on the day the cornerstone was laid : "It affords a beautiful and blessed illustration of the beneficence of our holy religion. . . . among the renowned heathen of antiquity were found the enduring monuments of power and pride and oppression, of selfishness and ambition; but of mercy to the miserable, not one. […] The edifice is to be the home of the helpless, outcast, persishing orphan—a temple of humanity—a monument of mercy."
Christian idealism was not the only force propelling the creation of the asylum: a rapidly growing New York was experiencing many of the social problems associated with industrialization in the 19th century. Ill equipped to handle these problems on such a scale, the city was in desperate need of institutions that would at least mitigate them. For a good portion of the century, Leake and Watts was able to perform this function well.
 Richard M. Hayden, An Historical Account of the Founding and Work of the Leake and Watts Orphan House New York City (New York: Leake and Watts Association, 1886), 16.
 Ibid., 18.
 Christopher Gray, « Streetscapes: The Leake & Watts Orphan Asylum; A Castoff in the Path of a Growing, Great Cathedral », New York Times, 24 juin 1990.
 Andrew Dolkart, Morningside Heights : a history of its architecture & development (New York: Columbia University Press, c1998), 20.
 Richard M. Hayden, Op. Cit., 17.