P-40's?
Awesome...the 409th flew Warhawks and Mustangs, it was part of the 372nd Fighter Group and participated in the Louisiana Maneuvers in the summer of '44. From their discussion page (http://www.armyairforces.com/dbgroups.asp?Group=193) you see the commanders of the 409th were:
Commanders
Name Dates
Maj Francis E Brenner 28 Oct 1943
Maj Darrell G Welch 21 Dec 1943
Maj Joseph S Wakefield 4 Feb 1944
Maj John R Harrison 16 Feb 1944
Lt Col Sam W Westbrook 3 Mar 1944
Lt Col Robert W Stephens 17 Mar 1945
Lt Col Jack J Oberhansly 30 May 1945
Col George R Bickell 6 Aug-7 Nov 1945
.....Westy.....