Bruce was born at Staunton Hill in Charlotte County, Virginia to Charles and Sarah Alexander (Seddon) Bruce (a sister of James Seddon), and received an academic education at Norwood High School and College in Nelson County, Virginia.

He later attended the University of Virginia where he bested Woodrow Wilson in both a highly contested formal debate and an essay competition.

In addition to his career in law, Bruce was also writer, and received a Pulitzer Prize in 1918 for his book Benjamin Franklin, Self-Revealed.

He served as head of the city law department of Baltimore from 1903 to 1908; as a member of the Baltimore Charter Commission in 1910; and as general counsel to the Maryland Public Service Commission from 1910 to 1922, at which time he resigned.

Bruce was defeated in the next election in 1928 by Republican Phillips Lee Goldsborough, and resumed the practice of law in Baltimore until 1937, when he retired.