Kirby, those are some interesting points you bring you up. I likewise find the U.S. governmentís response to Parsonsí death following the end of the French Intervention to be curious. I had never thought of Parsonsí death in relation to the U.S. governmentís prompting of the Mexican Liberals against the fleeing Confederates, but I think you may be very correct in your estimate that the Liberals took the U.S. governmentís promptings to heart when it came to Parsons and his companions. And I agree that it definitely reverberated throughout the Confederate community in Mexico. Iím quite familiar with the military situation on the Mexican border following the war (although it is largely outside of the focus of my current research), and there is no doubt that the U.S. was engaged in urging the Liberals to do what they could against the numerous Confederates crossing the Rio Grande. Iím not sure if this is the focus of your current project or not but I would be happy to forward anything that I might come across in my own research to you in regards to U.S. activities along the Mexican border following the Civil War.
So far I have not done extensive research in the Mexican archives, although you do illustrate the important materials available in them in your example. I have however looked heavily into French documents and accounts from the time, which I have found to be helpful. Although there has been comparatively little written about the Confederate exodus to Mexico and the U.S. military on the Mexican border following the Civil War, there is extensive documentation available for those who take the time to look for it. I am glad to know that others are also undertaking similar research into this often neglected area of study.