In common with France, Spain, Great Britain, and Germany, the United States was disturbed for the safety of the investments and persons of its citizens.

The Government was also concerned because the points of first and most persistent fighting were where the various railroads crossed the American boundary.

This circumstance brought the whole border within the range of disturbance.

The Government was apprehensive, too, as to the effect of long-continued war upon territories within the circle of its chief interest, the Caribbean area.

Yet, when the first surprise caused by the revolution had passed and the reason for the outbreak was perceived,--the fact that the order and apparent prosperity of the Diaz regime had been founded upon the oppression and exploitation of the masses,--public sympathy in the United States went out to Madero and his supporters.
The Diaz Government collapsed with surprising suddenness.