When Grant was elected president in 1868, Chipman was asked to be on the presidential inaugural committee. At the time, Chipman was living on the corner of First and B streets southeast. After Congress passed the District of Columbia Organic Act of 1871, Chipman was appointed Secretary of the District of Columbia, effectively the second highest local official after the Governor of the District of Columbia. Chipman held this position for 50 days, until Edward L. Stanton was appointed to replace him. At the time, Chipman was living at 1725 G Street NW, and he had recently founded the law firm of Chipman, Hosmer & Co., located at Sixth and F streets NW.