Law of the Plainsman is a Western television series starring Michael Ansara that aired on the NBC television network from October 1, 1959, until May 5, 1960. The character of Native American U.S. Marshal Sam Buckhart was introduced in two episodes of the popular ABC Western television series The Rifleman starring Chuck Connors as Lucas McCain. Law of the Plainsman is distinctive and unique in that it was one of the few television programs that featured a Native American as the lead character, a bold move for U.S.network television at that time. Ansara had earlier appeared in the series Broken Arrow, having portrayed the Apache chief, Cochise. Ansara, however, was not Native American but of Syrian descent. Ansara played Sam Buckhart, an Apache Indian who saved the life of a U.S. Cavalry officer after an Indian ambush. When the officer died, he left Sam money that was used for an education at private schools and Harvard University. After school, he returned to New Mexico where he became a Deputy Marshal working for Marshal Andy Morrison. He lived in a boarding house run by Martha Commager. The only other continuing character was 8-year old Tess Logan, an orphan who had been rescued by Buckhart. Robert Harland, later of Target: The Corruptors! starred in seven episodes as Deputy Billy Lordan. Wayne Rogers, who went on to star in another Four Star western, Stagecoach West, and later, M*A*S*H, also played deputy Lordan in several episodes.

In the Salinas Valley in and around World War I, Cal Trask feels he must compete against overwhelming odds with his brother for the love of their father. Cal is frustrated at every turn, from his reaction to the war, how to get ahead in business and in life, and how to relate to his estranged mother.