Henry L. Mitchell studied law and was admitted to the bar at the age of 18. He served in the Confederate States Army during the Civil War and was elected to the Florida House of Representatives while still in military service. Following his tenure in the legislature, Mitchell was appointed to the Florida Supreme Court, serving as an associate justice until 1891. He then transitioned to executive roles, being elected governor and later holding positions as clerk of the circuit court and county treasurer in Hillsborough County.

Henry L. Mitchell's political identity is marked by a fervent Southern nationalism, as evidenced by his expulsion of Masonic lodge members for Union Army service. His judicial career, including his tenure on the Florida Supreme Court, suggests a deeply rooted commitment to legal principles. Mitchell's unexpected legislative actions, such as being reelected to the Florida House of Representatives while serving in the Confederate Army, hint at a highly localized and ideologically driven approach to governance.