In 1855 he began study of law, was admitted to the bar in 1857, and opened an office in Washington Court House.

In 1859 he was elected Prosecuting Attorney of Fayette County, and served two terms.

In 1886, he was nominated by the Republicans for Supreme Court Judge, and defeated incumbent Democrat Martin Dewey Follett.

[5] Williams served as the first dean of the Ohio State University Moritz College of Law starting in 1891.

The law school opened to 23 students in the basement of the Franklin County Courthouse.