He outspokenly praised the efforts of "radical abolitionists", such as the Boston Vigilance Committee and the Massachusetts Anti-Slavery Society.

[2] During the Civil War, he entered the Union Army as captain of Company C, Thirteenth Regiment, Maine Volunteer Infantry.

[3] He served as delegate to the constitutional convention of Alabama in 1867, and as clerk of the circuit court of Mobile County in 1867 and 1868.

[4] Buck ran for Congress in 1868, to represent Alabama's 1st District, which at the time included both Selma and Mobile.

Due to the laws of the reconstruction government, most people who fought for the Confederacy were ineligible to vote in that election.

He was later appointed United States marshal for the northern district of Georgia by President Benjamin Harrison, and he served in such capacity from 1889 to 1893.

Buck explained to Japanese officials American policy regarding the Spanish-American War, the annexation of Hawaii, the Boxer Rebellion in China, and the "Open Door Notes" presented by Secretary of State John Hay to limit foreign control of China.