William Northcott was born in Murfreesboro, Tennessee, on January 28, 1854.

He joined the Republican Party and in 1896 he was elected to the office of the lieutenant governor of Illinois.

In this function he was the deputy of the Governors John Riley Tanner and his successor Richard Yates Jr.

Between 1905 and 1914 Northcott was the U.S. Attorney for the Eastern District of Illinois.

[2] William Northcott died on January 25, 1917, in Excelsior Springs, Missouri, and he was buried at Oak Ridge Cemetery in Springfield, Illinois.