They revived the New Service in .45 Colt, due to shortcomings in the .38 Long Colt during the Moro insurrection. The gun had been around since 1898, but the ones adopted by the military were designated Model of 1909. (They also equipped NCOs with Winchester 1897 shotguns, to help counter Moro tactics.)
In WWI, the 1909 was modified for .45ACP, and became the Colt 1917.