jan 1, 1917 - Constitution of 1917

Description:

Carranza, having gathered supporters and revolutionary leaders, held a constitutional congress, but there was a split in supporters of the San Luis Potosí and Guadalupe and, on the other side, the Plan of Ayala. The US supported Carranza, which led to conflicts between Carranza's opposing revolutionaries and the US as they raided US border towns. The final version of the constitution was ratified in 1917.

Sources:
http://countrystudies.us/mexico/29.htm