Van Buren as President was the political leader. Both Taylor and Scott led separate military expeditions: Taylor overland from the North, Scott by sea through Vera Cruz.
Texas
James K. Polk.
Mariano Guadalupe Vallejo led the Californio rebellion, until John C. Fremont led the Anglo rebellion on the same region.
The Mexican American War.
They led the revolts that eventually became the War of Independence of Mexico against Spain (1810 - 1821).
The annexation of Texas by the US. Border Conflicts. Failed negotiations to purchase Alta California an Nuevo Mexico.
The Mexican-American War (1846-1848) as well as the Second Franco-Mexican War (1861-1867) qualify as such.
The Zimmermann Telegramproposal from Germany to Mexico to make war against the United States. It was ignored by Mexico but angered Americans and led in part to the declaration of war in April.
The Battle of Mexico City when General Winfield Scott led his army into the large city to capture it.
In 1821 Mexico led the revolution against the country of Spain. This conflict is known as the Mexican War of Independence.
Germany's practice of unrestricted submarine warfare that led to the sinking of the Lusitania and the Zimmerman telegram, in which Germany promised Mexico its old lands in California, Arizona, and New Mexico if Mexico attacked the United States all led to the United States' entrance into World War I.
Germany... Germany sent a letter/telegraph to Mexico , which said that if Mexico allied to Germany , Germany would've recovered the territories that Mexico lost in a war with U.S ... U.S. intercepted this message which was the last event that "forced" U.S. into war...