He moved to a farm near Yellow Springs, Ohio in 1841 and continued the practice of law.

He served as member of the board of trustees of Antioch College in 1852.

He resumed the practice of law and engaged in agricultural pursuits near Yellow Springs.

He served as lieutenant colonel of the Ninety-fourth Regiment of Minutemen of Ohio in 1862.

Harlan moved to San Francisco, California, in 1864 and resided there until his death on January 8, 1868.