I can understand the Redskins being offended, but immortalizing the American Indian by proudly naming a team after them seems like a silly thing to be offended by... and yes originally it was named after the mayor of KC.
http://en.wikipedia.org/wiki/Harold_Roe_Bartle
After Bartle helped lure the Dallas Texans American Football League team to Kansas City in 1962, owner Lamar Hunt renamed the franchise the Kansas City Chiefs after Bartle's nickname, "The Chief."