He attended the public Southeast Missouri State Teachers College at Cape Girardeau, and Valparaiso University. In 1912 he graduated from the law department of the University of Kentucky at Lexington, in which year he was admitted to the bar and began practicing in Searcy, Arkansas.
During this time, he was also active in banking, while remaining interested in politics. He was a delegate to the state constitutional convention in 1918, and he served from 1919 to 1922 as a prosecuting attorney on the state"s first judicial circuit. He was elected in 1930 to the United States House of Representatives, serving there until his resignation in 1937 to become a senator
He had been elected to the Senate to fill the vacancy caused by the death of Joseph T. Robinson.
Although the term ended in 1943, Miller resigned in 1941 to take up his appointment as a judge for the United States District Court for the Western District of Arkansas. He was one of the district judges in the Little Rock Nine case.
He retired from his post in 1967 and became a senior district judge. Miller lived in Fort Smith, Arkansas until his death on January 30, 1981.
Delaware Arkansas Constitutional Convention, 1918. Member Arkansas Bar Association (award 1966), Masons (32 degree), Shriners.
Married Ethel Lucile Lindsey, October 21, 1914 (deceased). Children: Mary Louise, John E. Married second, Ethel L. Skinner, December 27, 1956.