[BroJoeK]

1869 painting Alegoría de la Constitución de 1857:

Homer_J_Simpson: "I wonder if the rebel side sent emissaries to Washington to persuade the U.S. government to recognize them as the legitimate Mexican government."

Not that I know of, just the opposite:

"The Liberals wanted to eliminate the political, economic, and cultural power of the Catholic church as well as reduce the role of the Mexican Army.
Both the Catholic Church and the Army were protected by corporate or institutional privileges (fueros) established in the colonial era...

"The government of U.S. President James Buchanan recognized the [Liberal] Juárez regime in April 1859 and the U.S. and the government of Juárez negotiated the McLane-Ocampo Treaty, which if ratified would have given the Liberal regime cash but also granted the U.S. transit rights through Mexican territory..."

President Buchanan's administration was highly sympathetic to the liberal cause and their new Constitution of 1857.

But the defeat of Mexican conservatives (monarchists) in 1860 was far from the end of this story, as France's Napoleon III intervened at the end of 1861...

[Homer_J_Simpson]

Not that I know of, just the opposite:

That's about what I was thinking. I put my question as I did because I was thinking of another rebel cause - not quite fully formed - that will be appealing to European powers for legitimacy and intervention.