Robert McClelland was born in 1807 in Greencastle, Pennsylvania. He attended Dickinson College, studied the law, was admitted to the state bar, and established a law practice in Michigan.

In 1835, McClelland was elected as a member of Michigan's constitutional convention. From 1839 to 1840, and again in 1843, he served as a Democrat in the state legislature before being elected to the United States House of Representatives, where he served from 1843 to 1849. From 1852 to 1853, McClelland served as governor of Michigan before resigning his post to become President Franklin Pierce's secretary of the interior.

McClelland served as head of the Interior Department until the end of the Pierce administration in 1857. He then returned to Michigan, where he worked as a lawyer and served as a member of Michigan's constitutional convention in 1867. Robert McClelland died in 1880.