Posted: Saturday, June 9, 2012 --- 2:30p.m.

APPLETON, Wis. (AP) -- Herb Kohl, who has represented Wisconsin in the U.S. Senate since 1988, expressed gratitude to fellow Democrats Saturday in his farewell speech at the state party's annual convention in Appleton.

The 77-year-old Kohl announced last May that he would not be seeking re-election. Kohl told Democrats that it's been the greatest honor and responsibility in his lifetime to represent Wisconsin in the Senate.

Kohl has served four 6-year terms, winning his first term with the slogan "nobody's senator but yours." The Milwaukee Bucks owner told Democrats that he's not going anywhere and would be around to help the party in the years to come.

The Appleton Post-Crescent reports Milwaukee Mayor Tom Barrett said Democrats should recognize the "incredible commitment" Kohl has made to Wisconsin, not just in the Senate, but throughout his life.

Copyright 2012. The Associated Press.