You can either call Colt or look it up at Proofhouse.com
@1969
1970
1959
1929
and the model is..................................
if your pistol is of the model 1911 with serial number 189558 then it was made in 1917 by colt. If it is the revolver then the serial number is to high for the 1917 revolver.
1971
1919-1922
made about 1958
Manufactured in 1950
Proofhouse.com has Colt sn data.
1907-1909