The regime of the the tottering old dictator, Porfirio Diaz, had been in power practically since the end of the American Civil War. Managing to be reelected time after time in rigged elections, Don Porfirio ruled Mexico with an iron hand, allowing his storm troopers, the dreaded "rurales" to terrorize the peasants into abject submission.
Matters came to a head at the mine at Cananea, Sonora, in 1906 when striking miners were violently repressed by gun wielding American company thugs.
This and other minor rebellions set the stage for a major uprising just four years later, in 1910. The struggle that would follow would eventually leave a million casualties in bloody conflicts all over the country, and send Diaz into permanent exile in France.