Federal Constitution of the United Mexican States of 1857 in the context of "Universal manhood suffrage"

In the history of Mexico, La Reforma (from Spanish: "The Reform"), or reform laws, refers to a pivotal set of laws, including a new constitution, that were enacted in the Second Federal Republic of Mexico during the 1850s after the Plan of Ayutla overthrew the dictatorship of Santa Anna. They were intended as modernizing measures: social, political, and economic, aimed at undermining the traditional power of the Catholic Church and the army. The reforms sought separation of church and state, equality before the law, and economic development. These anticlerical laws were enacted in the Second Mexican Republic between 1855 and 1863, during the governments of Juan Álvarez, Ignacio Comonfort and Benito Juárez. The laws also limited the ability of Catholic Church and Indigenous communities from collectively holding land. The liberal government sought the revenues from the disentailment of church property, which could fund the civil war against Mexican conservatives and to broaden the base of property ownership in Mexico and encouraging private enterprise. Several of them were raised to constitutional status by the constituent Congress that drafted the liberal Constitution of 1857. Although the laws had a major impact on the Catholic Church in Mexico, liberal proponents were not opposed to the church as a spiritual institution, but rather sought a secular state and a society not dominated by religion.

The Juárez Law reduced the power that military and ecclesiastical courts held. The Lerdo Law forced land held in collective ownership to be sold to individual owners. It aimed at creating a dynamic real estate market, creating a class of yeoman farmers owning their own land, and raising revenue for the state. The measure was intended to strip the Church of most of its property, as well as to break Indigenous communities' collective ownership of land.

The Reform War (17 December 1857 – 11 January 1861) or War of Reform (Spanish: Guerra de Reforma), also known as the Three Years' War (Spanish: Guerra de los Tres Años), and the Mexican Civil War, was a complex civil conflict in Mexico fought between Mexican liberals and conservatives with regional variations over the promulgation of Constitution of 1857. It has been called the "worst civil war to hit Mexico between the War of Independence of 1810–21 and the Revolution of 1910–20". Following the liberals' overthrow of the dictatorship of conservative Antonio López de Santa Anna, liberals passed a series of laws codifying their political program. These laws were incorporated into the new constitution. It aimed to limit the political power of the executive branch, as well as the political, economic, and cultural power of the Catholic Church. Specific measures were the expropriation of Church property; separation of church and state; reduction of the power of the Mexican Army by elimination of their special privileges; strengthening the secular state through public education; and measures to develop the nation economically.

The constitution had been promulgated on 5 February 1857 was to come into force on 16 September 1857. There was intense opposition from Conservatives and the Catholic Church over its anti-clerical provisions, but there were also moderate liberals, including President Ignacio Comonfort, who considered the constitution too radical and likely to trigger a civil war. The Lerdo Law forced the sale of most of the Church's rural properties. The measure was not exclusively aimed at the Catholic Church, but also Mexico's indigenous peoples, which were forced to sell sizeable portions of their communal lands. Controversy was further inflamed when the Catholic Church decreed the excommunication of civil servants who took a government-mandated oath upholding the new constitution, which left Catholic civil servants with the choice of losing their jobs or being excommunicated.

The current Constitution of Mexico, formally the Political Constitution of the United Mexican States (Spanish: Constitución Política de los Estados Unidos Mexicanos), was drafted in Santiago de Querétaro, in the State of Querétaro, Mexico, by a constituent convention during the Mexican Revolution. It was approved by the Constituent Congress on 5 February 1917, and was later amended several times. It is the successor to the Constitution of 1857, and earlier Mexican constitutions. "The Constitution of 1917 is the legal triumph of the Mexican Revolution. To some it is the revolution."

The current Constitution of 1917 is the first such document in the world to set out social rights, preceding the Russian Soviet Federative Socialist Republic Constitution of 1918 and the Weimar Constitution of 1919. Some of the most important provisions are Articles 3, 27, and 123; adopted in response to the armed insurrection of popular classes during the Mexican Revolution, these articles display profound changes in Mexican politics that helped frame the political and social backdrop for Mexico in the twentieth century. Article 3 established the basis for free, mandatory, and secular education; Article 27 laid the foundation for land reform in Mexico; and Article 123 was designed to empower the labor sector, which had emerged in the late nineteenth century and which supported the winning faction of the Mexican Revolution.

The Plan of Ayutla was the 1854 written plan aimed at removing conservative, centralist President Antonio López de Santa Anna from control of Mexico during the Second Federal Republic of Mexico period. Initially, it seemed little different from other political plans of the era, but it is considered to be the first act of the Liberal Reform in Mexico. It was the catalyst for revolts in many parts of Mexico, which led to the resignation of Santa Anna from the presidency, never to vie for office again. The next Presidents of Mexico were the liberals, Juan Álvarez, Ignacio Comonfort, and Benito Juárez. The new regime would then proclaim the 1857 Mexican Constitution, which implemented a variety of liberal reforms.

In Mexican history, the Plan of Tuxtepec was a plan drafted by General Porfirio Díaz in 1876 and proclaimed on 10 January 1876 in the Villa de Ojitlán municipality of San Lucas Ojitlán, Tuxtepec district, Oaxaca. It was signed by a group of military officers led by Colonel Hermenegildo Sarmiento and drafted by porfiristas Vicente Riva Palacio, Ireneo Paz, and Protasio Tagle on the instigation of Díaz. Díaz signed the previous version of the plan in December 1875, which did not include the three most important articles that appointed Diaz as president. It disavowed Sebastián Lerdo de Tejada as President, while acknowledging the Constitution and the Reform laws, and proclaimed Díaz as the leader of the movement. Díaz later became the president of Mexico, ushering in a period known as the Porfiriato.

The office of the vice president of Mexico was first created by the Constitution of 1824, then it was abolished in 1836 by the Seven Constitutional Laws, then briefly restored in 1846 following the restoration of the Constitution of 1824 and lasted a year until 1847 where it was again abolished through a constitutional amendment, it was later restored in 1904 through an amendment to the Constitution of 1857, before being finally abolished by the current Constitution of 1917. Many Mexican vice presidents acted as president during time between the end of the First Mexican Empire and the establishment of the Second Mexican Empire.