Ignacio Comonfort in the context of "Federal Constitution of the United Mexican States of 1857"

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 Political Constitution of the Mexican Republic of 1857 (Spanish: Constitución Política de la República Mexicana de 1857), often called simply the Constitution of 1857, was the liberal constitution promulgated in 1857 by Constituent Congress of Mexico during the presidency of Ignacio Comonfort. Ratified on February 5, 1857, the constitution established individual rights, including universal male suffrage, and others such as freedom of speech, freedom of conscience, freedom of the press, freedom of assembly, and the right to bear arms. It also reaffirmed the abolition of slavery, debtors' prisons, and all forms of cruel and unusual punishment such as the death penalty. The constitution was designed to guarantee a limited central government by federalism and created a strong national congress, an independent judiciary, and a small executive to prevent a dictatorship. Liberal ideals meant the constitution emphasized private property of individuals and sought to abolish common ownership by corporate entities, mainly the Catholic Church and indigenous communities, incorporating the legal thrust of the Lerdo Law into the constitution.

A number of articles were contrary to the traditional powers of the Catholic Church, such as the ending of Catholicism as official religion, the nationwide establishment of secular public education, the removal of institutional fueros (legal privileges), and the forced sale of Church property. Conservatives strongly opposed the enactment of the constitution, which polarized Mexican society. The Reform War (1858-1860) began as a result, with liberals winning on the battlefield over conservatives. The losing conservatives sought another way back into power, and their politicians invited Maximilian I of Mexico, a Habsburg, to establish a Mexican monarchy with the Church's support. The republican government-in-domestic-exile was headed by President Benito Juárez as the legitimate Mexican government under the constitution. With the ouster of the French and the defeat of the conservatives in 1867, the Restored Republic was again governed under the 1857 Constitution. The constitution was durable but its provisions not always followed in practice. It was revised in 1874 to create a Senate. It remained as Mexico's constitution until 1917 although many of its provisions ceased to be enforced.

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 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.

The Lerdo Law (Spanish: Ley Lerdo) was the common name for the Confiscation of Law and Urban Ruins of the Civil and Religious Corporations of Mexico, part of La Reforma. It targeted not only property owned by the Catholic Church, but also properties held in common by indigenous communities and transferred them to private hands. Liberals considered such corporate ownership as a major impediment to modernization and development in Mexico. Drafted by Miguel Lerdo de Tejada, it was signed on 25 June 1856 by President Ignacio Comonfort, but its language was ambiguous, needing subsequent clarifications.

Its objectives were to create a market in rural real estate and incentivize development; create rural middle class, improve public finances of the state, and revive the economy by eliminating restrictions on freedom of movement. Properties were to be sold to private individuals, which was expected to stimulate the real estate market and to generate government revenue by a sales tax. Much property held by the Catholic Church was urban and exempt from confiscation. The impact was felt most by indigenous communities, now forced to break up holdings held in common that had allowed communities to retain control of their land. The rural poor lacked the funds to buy property and pay the transfer fees. Most purchasers were large landowners or foreign investors, which further concentrated land ownership. Religious groups and their civil corporations were prohibited from purchasing land sold under law unless for strictly-religious purposes. Implementation of the law was disrupted by the Reform War (1858–60) and the French Intervention (1862–67), but resumed with the defeat of the French invaders and their Conservative allies in 1867. Implementation resumed after that, but not until the regime of Porfirio Díaz was the impact felt significantly.