The district, located in the Chicago metropolitan area, includes parts of Arlington Heights, Hoffman Estates, Des Plaines, Mount Prospect, Rolling Meadows, Barrington, Inverness, Palatine, Prospect Heights and South Barrington.

Walker served in the United States Army during the Vietnam War and during his service was awarded a Bronze Star.

He has also been a soccer coach and member of the Arlington Heights Park District Foundation board, and has co-chaired the Northwest Suburban Veterans Advisory Council.

[3][4] In 2008, Walker defeated Republican candidate and Elk Grove Village trustee Christine Prochno to succeed outgoing Representative Carolyn Krause.

Walker was defeated in the 2010 general election by Republican David Harris who preceded Krause in the Illinois House.