He attended public elementary school in Nashville and the Castle Heights Military Academy in Lebanon, Tennessee.

He returned to private practice in Nashville as a partner in the firm Gullett, Steele, Sanford, Robinson and Merritt from 1970 to 1970, specializing on federal civil and criminal litigation.

Merritt served as a lecturer at Vanderbilt University Law School from 1973 to 1975 and as executive secretary of the Tennessee Code Commission in 1977.

[1] President Jimmy Carter nominated him to the United States Court of Appeals for the Sixth Circuit on August 25, 1977, for the seat vacated by Judge William Ernest Miller.

Thomas L. Friedman, writing for The New York Times at the time, wrote that Merritt "is considered a moderate who would generate some Republican support" but noted that reports of his consideration "drew the ire" of the Simon Wiesenthal Center, which "criticized Judge Merritt for ordering an inquiry into the Justice Department's handling of the extradition of John Demjanjuk, who was convicted of Nazi war crimes by an Israeli court.