Born in Charleston, South Carolina, Mills was one of the first American-born architects. From 1800 to 1802 Mills studied architecture under the direction of James Hoban before relocating to Philadelphia. It was in this new city that the young architect began a mentorship with Benjamin Henry Latrobe from whom he gained a thorough knowledge of Classical Revival style. In 1808 Mill opened his own architectural firm and began acquiring important Philadelphia commissions. These works included Washington Hall, an expansion of Independence Hall and the Octagon Unitarian Church. In 1815 Mills moved to Baltimore where he designed the city’s Washington Monument and laid out the design for Mount Vernon place. He was also responsible for St. Johns Episcopal Church and the Maryland House of Industry. Due to financial straits, Mills left Baltimore in 1820, relocating his family to South Carolina then Richmond, and finally Washington, DC. During this time, he served as the South Carolina Superintendent of Public Buildings and surveyed the planned Susquehanna River Canal. In Washington he completed alterations to important federal buildings including the Capital before winning a competition for the design of the Washington National Monument. Mills was eventually appointed the Architect of Public Buildings serving in that position until 1842. Benjamin Mills died in Washington DC in 1855. He is buried in the Congressional Cemetery.