- 
  
   – The Army of the Three Guarantees enters Mexico – The Army of the Three Guarantees enters Mexico
 City on September 27, symbolically ending Spanish colonial rule.
- 
  
   Signed on August 24, this treaty confirms Mexican Signed on August 24, this treaty confirms Mexican
 independence from Spain.
- 
  
   The crisis in Spain (including the deposition of The crisis in Spain (including the deposition of
 the Spanish king) undermines Spanish authority over its colonies, setting the
 stage for independence movements in New Spain.
- 
  
   On September 16, Father Miguel Hidalgo y Costilla issues On September 16, Father Miguel Hidalgo y Costilla issues
 the call to arms in Dolores, Guanajuato, marking the beginning of the Mexican
 War of Independence.
- 
  
   – Spanish royalist forces defeat insurgent armies, – Spanish royalist forces defeat insurgent armies,
 forcing the revolutionary movement to regroup and adapt it
- 
  
   – Insurgent leaders promulgate this constitution as – Insurgent leaders promulgate this constitution as
 a framework for self-governance and the establishment of an independent
 state.
- 
  
   – After early setbacks, Vicente Guerrero emerges as – After early setbacks, Vicente Guerrero emerges as
 a key leader, sustaining the fight for independence in southern Mexico
- 
  
   Agustín de Iturbide proclaims a plan based on three Agustín de Iturbide proclaims a plan based on three
 guarantees—independence, equality, and protection of the Catholic
 faith—that unites royalists and insurgents.
- 
  
   Political changes in Spain (including the Political changes in Spain (including the
 reinstatement of the Cadiz Constitution) influence reforms in New Spain and
 open a path toward negotiations with insurgent forces.
- 
  
  Agustín de Iturbide is declared
 Emperor of Mexico, marking the nation's first attempt at an independent
 monarchical system.
- 
  
   Facing internal opposition and instability, Facing internal opposition and instability,
 Iturbide abdicates in March, paving the way for a republican form of
 government
- 
  
  Promulgated on October
 4, this constitution establishes Mexico as a federal republic.
- 
  
  Political struggles between federalist and
 centralist factions intensify as Mexico works to consolidate its new state.
- 
  
  Discontent grows among settlers in the
 Mexican province of Texas, eventually leading to an armed rebellion against
- 
  
  On March 2, Texas declares its
 independence from Mexico following pivotal conflicts such as the siege of the
 Alamo and the victory at San Jacinto
- 
  
  The Republic of Texas is annexed
 by the U.S., a move that heightens tensions between Mexico and the United
- 
  
  Disputes over the Texas border and
 American expansionism lead to war on April 25.
- 
  
  – Signed on February 2, this treaty ends the
 Mexican–American War. As a result, Mexico cedes vast territories—including
 what are now Texas and California—to the United States