In response to Madero's letter to action, Pascual Orozco (a wealthy mining baron) and Chihuahua Governor Abraham González formed a powerful military union in the north, taking military control of several northern Mexican cities with other revolutionary leaders, including Pancho Villa. Against Madero's wishes, Orozco and Villa fought for and won Ciudad Juárez. After militias loyal to Madero defeated the Mexican federal army, on May 21, 1911, Madero signed the Treaty of Ciudad Juárez with Díaz. It required that Díaz abdicate his rule and be replaced by Madero. Insisting on a new election, Madero won overwhelmingly in late 1911, and he established a liberal democracy and received support from the United States and popular leaders such as Orozco and Villa. Orozco eventually became disappointed with the Madero's government and led a rebellion against him. He organized his own army, called "Orozquistas"—also called the Colorados ("Red Flaggers")—after Madero refused to agree to social reforms calling for better working hours, pay and conditions. The rural working class, which had supported Madero, now took up arms against him in support of Orozco.