Illinois Congressmen 1960's

This vintage 'Abraham Lincoln' first day cover, canceled on May 28, 1966 is hand signed by the following 9 Congressmen from Illinois from the 1960's: O'Hara, Springer, Reid, Michel, Collier, Anderson, Rostenbowski, Annunizio and Arends. There is also a signature of William T. Murphy which appears to be either that of a stamp or autopen machine and is not a hand signed authentic signature.