nts officially, the American
Government resorted to all kinds of means to oust the dictator. An
embargo was laid on the export of arms and munitions; all efforts to
procure financial help from abroad were balked. The power of Huerta was
waning perceptibly and that of the Constitutionalists was increasing
when an incident that occurred in April, 1914, at Tampico brought
matters to a climax. A number of American sailors who had gone ashore
to obtain supplies were arrested and temporarily detained. The United
States demanded that the American flag be saluted as reparation for the
insult. Upon the refusal of Huerta to comply, the United States sent a
naval expedition to occupy Vera Cruz.

Both Carranza and Huerta regarded this move as equivalent to an act of
war. Argentina, Brazil, and Chile then offered their mediation. But
the conference arranged for this purpose at Niagara Falls, Canada,
had before it a task altogether impossible of accomplishment. Though
Carranza was willing to have the Constitutionalists represented, if
the discussion related solely to the immediate issue between the United
States and Huerta, he declined to extend the scope of the conference so
as to admit the right of the United States to interfere in the internal
affairs of Mexico. The conference accomplished nothing so far as the
immediate issue was concerned. The dictator did not make reparation for
the "affronts and indignities" he had committed; but his day was over.
The advance of the Constitutionalists southward compelled him in July
to abandon the capital and leave the country. Four months later the
American forces were withdrawn from Vera Cruz. The "A B C" Conference,
however barren it was of direct results, helped to allay suspicions of
the United States in Hispanic America and brought appreciably nearer a
"concert of the western world."

While far from exercising full control throughout Mexico, the "first
chief" of the Constitutionalists was easily the dominant figure in
the situation. At home a ranchman, in public affairs a statesman of
considerable ability, knowing how to insist and yet how to temporize,
Carranza carried on a struggle, both in arms and in diplomacy, which
singled him out as a remarkable character. Shrewdly aware of the
advantageous circumstances afforded him by the war in Europe, he turned
them to account with a degree of skill that blocked every attempt at
defeat or compromise. No matter how serious the opposition to hi