Sonora had been a Mexican province during the early 19th century. Most of the problems they faced were with the local Apache, whom many northern residents distrusted and hated. In 1881, the Empire of Mexico was bankrupt and in order to pay its creditors, sold the provinces of Sonora and Chihuahua to the Confederate States for three million dollars. This triggered the Second Mexican War, but the province saw no action as the CS Army chose to take the fight to the enemy rather than sit and wait for them. Upon the successful conclusion of that campaign, tensions between the local Mexicans and Apache Indians exploded into violence, which the CS Army had to suppress.