During his time as Commissioner of Public Buildings, he played a role in extending the U.S. Capitol and building the Capitol Dome. He also oversaw a number of historical events including the Gettysburg Address and the funeral of Abraham Lincoln.

Benjamin Brown French was born September 4, 1800, in Chester, New Hampshire, to Daniel and Mercy French. He married Elizabeth Richardson in 1825, and served as a representative in the New Hampshire legislature between 1831 and 1833.

French was appointed and served as Clerk of the United States House of Representatives from 1845-1847. From 1847-1850, he served as president of the Magnetic Telegraph Company overseeing the expansion of telegraph communications throughout the United States.

In 1853, French was named the Commissioner of Public Buildings under President Franklin Pierce and was the chief marshal of the March 1861 inaugural parade of Abraham Lincoln, who reappointed French Commissioner of Public Buildings. As the Commissioner of Public Buildings, French was responsible for the care of all federal buildings in Washington, D.C., including the United States Capitol.   

During his tenure, French also oversaw the funeral arrangements for both Willie Lincoln (1850–1862) and President Lincoln (1809–1865).

On March 4, 1867, Republicans in Congress abolished the office of commissioner as a way for punishing French for his loyalty to President Andrew Johnson. On March 14, 1867, French surrendered books, ledgers and accounts to the Secretary of the Interior. On March 30, 1867, Congress placed the care of the U.S. Capitol and grounds under Edward Clark and the newly created office of the Architect of the Capitol. 

French spent his final years in a minor clerk position in the U.S. Treasury Department until two months before his death on August 12, 1870.