Brock was born near Columbus, Nebraska.

He graduated from Leigh High School and then the College of Pharmacy of the University of Nebraska-Lincoln in 1929.

He then became a cattle feeder and farmer and the president of Nebraska Livestock Feeders Association, Cornbelt Livestock Feeders Association, and Northeast Nebraska Rural Electric Association.

Brock was a member of the Nebraska Highway Advisory Commission and then a delegate to the 1956 Democratic National Convention He was the chair of the Nebraska Democratic Party from 1954 to 1956.

In 1958 he was elected to the Eighty-sixth United States Congress serving from January 3, 1959 to January 3, 1961, and failed in his bid to be reelected in 1960.