His work includes roles in notable productions such as The Birth of a Nation (1915), Intolerance (1916), The Three Musketeers (1921), Oliver Twist (1922), The Cat and the Canary (1927), and The Man Who Laughs (1928).

His more notable roles include Silas Lynch in D.W. Griffith's The Birth of a Nation (1915), Cyrus the Great in Intolerance (1916), Porthos in The Three Musketeers (1921), Bill Sikes in Oliver Twist (1922), the guard in the 1927 film The Cat and the Canary, and Dr. Hardquanonne in The Man Who Laughs, which was completed in 1927 but released in 1928.

In 1919, Siegmann served as a director for Universal Pictures' production of the five-reel horror film The Trembling Hour starring Kenneth Harlan and Helen Eddy.

[2] Siegmann's career almost ended early, in 1915, when he was seriously injured while riding as a passenger in a car driven by fellow film actor and director Tod Browning.

Booth died instantly, and Siegmann suffered four broken ribs, a deeply lacerated thigh, and internal injuries.