If you are referring to Colt model 1911 or 1911A1 Government issue pistols, it was because there was a need for increased production .During WWI ,they were also made by Remington Arms UMC & Springfield Armory. During WWII besides Colt, they were also made by Ithaca,Remington Rand and Union Switch & Signal, Also about 500 each made by Singer Mfg and H&R.
Made in 1945 in Ithaca for Colt.
it was made by ITHACA (not colt) in 1943.................If your slide reads Colt, then sometime down the road a colt slide was put on your Ithaca receiver...............that is not unusual to have happen.................
made by Colt in 1918. your colt has an Ithaca slide, which often happens during cleaning
probably made by colt in 1943. If your slide reads Ithaca, then it is on a Colt frame. That is not unusual....................
if it's a 1911 45cal. pistol then it was made by Colt. the slide made be ITHACA, but the frame is Colt. it often happened when guns were cleaned in the field. Also, if it's a pistol it was made in 1917.
made about 1917
made by Colt in 1913. your slide probably reads 'Ithaca' . during field cleaning gun parts get mixed during re-assembly.
made in 1945
Made between 1944. /1945 in Ithaca for Colt.
your 45 pistol was made by Ithaca in 1945. if your slide reads Colt that indicats someone put a colt slide on your Ithaca frame, which is not unusual in the military. value depends on over all condition.
about 1945
about 1917