McKinney moved to Michigan in 1837, where he settled in Van Buren County.
[1] On November 1, 1847, McKinney was elected to the Michigan House of Representatives where he represented the Van Buren County district from January 3, 1848, to April 3, 1848.
On November 6, 1848, McKinney was elected to the Michigan Senate where he represented the 4th district from January 1, 1849, to April 2, 1849.
On November 5, 1849, McKinney was elected to another term in the Michigan Senate where he again represented the 4th district from January 7, 1850, to April 21, 1850.
[1] McKinney died in Van Buren County on July 10, 1870.