The first children were admitted to the Foundling Hospital on March 25, 1741, into a temporary house located in Hatton Garden. In September 1742, the stone of a new Hospital was laid in the area known as Bloomsbury Fields, lying north of Great Ormond Street and west of Gray's Inn Lane. The western wing was finished in October 1745. An eastern wing was added in 1752 "in order that the girls might be kept separate from the boys."
The new Hospital was described as "the most imposing single monument erected by eighteenth century benevolence" and became London's most popular charity.
William Hogarth, who was childless, had a long association with the Hospital and was a founding Governor. He designed the children's uniforms and the Coat of Arms, and he and his wife Jane fostered foundling children. Contemporary English artists decorated the walls of the hospital with their works.