Answer:
The Mexican Revolution, which began in 1910, ended dictatorship in Mexico and established a constitutional republic. A number of groups, led by revolutionaries including Francisco Madero, Pascual Orozco, Pancho Villa and Emiliano Zapata, participated in the long and costly conflict. Though a constitution drafted in 1917 formalized many of the reforms sought by rebel groups, periodic violence continued into the 1930s.
Explanation:
First of all, the Spanish (along with the rest of the large European countries at the time) had guns and other military technology. With the advantage of having gunpowder, the Spanish were able to relatively easily conquer the indigenous peoples in the Americas. Another point is the Spanish military training; the American civilizations had no military training that matched the strict codes of the European countries, so the precision of the Spanish helped them conquer.