I read a book about the "San Patricio Batallion" I forget the name of it but in all 72 were captured and 50 were executed, 30 at Chapultepec, the 16 at San Angel,4 at Mixocac Village(2 were hanged and 2 were killed by firing squad, only reason they were shot was because they were captured and joined under protest and did not fire on U.S troops). One San Patricio was recognized when Chapultepec surrendered and was shot on sight. Most Patricio's did not live off of the Mexican land since there were a large number of fraudulent claims by other deserters who tried to pass themselves off as Patricios.
Interesting note, the effectiveness of the San Patricio's led indirectly to the rise of ethnic units such as the Irish Brigade, the IX corp and other units as they felt Irish would fight better with fellow Irish and the same with Germans