In order to usher in this new Map Thread, let's reflect for a minute. This thread is not an IM service, to spam as you wish. Also, let's try to get some quality back in this tradition.
Anywho, new map, never before seen (except by the Strangemapsguy, and myself).
The map basically boils down to this: when the US gets word of the Zimmerman Telegram, public sentiment against Mexico and Germany are high. However, two things happen. One is that Germany holds off their unrestricted submarine warfare for another few months, and the second is that there is a major border raid conducted by Pancho Villa, an infamous Mexican revolutionary.
Papers gobble this up. Several more such events take place, and finally, the public is clamoring for war against Mexico. Thus, by April, the United States invades Mexico. It is obvious from the start that the Mexicans are fighting a hopeless war; even though they have German funds, there is no where else in the Western hemisphere where they can acquire weapons. By the end of the year, the US has captured Mexico City, although resistance carries on for quite some time.
At the end of the war in 1918, Mexico is a failed state. The American invasion has brought economic collapse to an economically starved nation. Rival factions fight over who controls what, while the American people have to decide what to do with this mess on their hands.
Although the US had intended to leave the US whole (minus a few northern territories), this complete collapse brings about a different outcome. The territories of Baja California (Baja California and Baja California Sur), Sonora and Chihuahua are given a plebiscite over whether to gain independence, or join the US. Although later some would question the legitimate of the election, these three territories overwhelmingly choose to join the US.
Meanwhile, in central Mexico, the formerly small Socialist Workers Party is starting to take hold. With a mixture of limited American control and encouragement from the newly Bolshevik Russia, the People's Republic of Mexico is founded. The US is completely thrown off and instantly retaliates, but fighting is slow and the casualties are high. Although the US never fully recognizes the PRM, they set up the puppet Republics of the Rio Grande and Aztlan (although the latter is largely neutral). Finally, the distant Yucatan is left to their own devices, and declares their own free state.