[1][4] After a brief period of time in Pennsylvania, Harris moved to Arlington Heights, Illinois where he and his wife reside.

In 1971, he attended Officer Candidate School and returned to serve as a platoon leader in the 471st Military Police Company of the District of Columbia Army National Guard.

In 1980, he joined the Illinois Army National Guard as an assistant correctional officer with the 33rd Military Police Battalion in Chicago.

[3] In July 1999, George Ryan named Harris the Adjutant General of Illinois to succeed Richard Austin.

[2] Harris served on Ronald Reagan's national advance staff in the 1976 Republican primary, and presidential elections of 1980 and 1984.

His opponent in the general election was Democratic activist and Elk Grove Park Board commissioner Joan E.

[11][12] After his loss, he joined the Illinois Hospital & Health Systems Association as the Senior Vice President for Government Relations.

[5] In 2010, Harris ran again for the Illinois House of Representatives against incumbent Democrat Mark Walker in the 66th district.

Harris was later reappointed to the position in 2023 at the beginning Pritzker's second term as Governor and was again unanimously confirmed by the Illinois Senate.