Gadsden Purchase


The Gadsden Purchase was an agreement between the United States and Mexico where the U.S. purchased land. The treaty established the southern border and helped fulfill America’s Manifest Destiny.

Franklin Pierce, 14th President of the United States. Image Source: Google Arts & Culture.

Gadsden Purchase Summary

The Gadsden Purchase was an agreement between the United States and Mexico in which the U.S. paid Mexico $10 million for 29,670 square miles of land, which is part of Arizona and New Mexico. Initially, the U.S. wanted more land, to be used for a Southern Transcontinental Railroad, but negotiations, led by James Gadsden, settled on the smaller area. The treaty did not resolve all tensions between the two nations, however, it did complete America’s Westward Expansion and established the southern border of the U.S.

Manifest Destiny Map, US Territorial Acquisitions, LOC
This map of the U.S. territorial acquisitions shows the Gadsden Purchase. Image Source: Wikimedia.

Gadsden Purchase Facts


  • September 25, 1853 — James Gadsden and Antonio de Santa Anna opened negotiations.
  • December 30, 1853 — The date the initial treaty was signed.
  • April 25, 1854 — The United States Senate approved a revised version of the treaty.
  • June 8, 1854 — Santa Anna signed the revised treaty.
  • June 30, 1854 — The Gadsden Purchase went into effect.


  • James Gadsden — The U.S. Minister to Mexico who negotiated the treaty.
  • Franklin Pierce — The U.S. President who sent James Gadsden to negotiate with Mexico and signed the revised treaty. Pierce was the 14th President of the United States.
  • Antonio de Santa Anna — The President of Mexico during the negotiations.
  • Christopher Ward — An agent for U.S. investors in the Garay Project who relayed instructions to Gadsden.


  • Also Known As — Treaty of La Mesilla.
  • Land Acquired — 29,670 square miles.
  • Location — Arizona and New Mexico.
  • Payment — The United States paid Mexico $10 million.
  • Part of — America’s Manifest Destiny and Westward Expansion.


The purpose of the Gadsden Purchase was to secure land for a Southern Transcontinental Railroad and resolve border disputes between the United States and Mexico.

Gadsden Purchase Significance

The Gadsden Purchase is important to American History because it completed the formation of the Continental United States — from the East Coast to the West Coast. It essentially ended America’s Westward Expansion by fulfilling Manifest Destiny.

Gadsden Purchase History

The Gadsden Purchase, also known as the Gadsden Treaty, was a significant agreement between the United States and Mexico that was finalized in 1854. In this agreement, the United States paid Mexico $10 million to acquire a 29,670 square-mile area of land. This land is now part of the states of Arizona and New Mexico.

The primary reason for the Gadsden Purchase was to obtain land that would allow for the construction of a Southern Transcontinental Railroad. Additionally, this agreement aimed to resolve some remaining conflicts between the United States and Mexico following the Mexican-American War, which had ended in 1848.

Tension After the Mexican-American War

The Treaty of Guadalupe Hidalgo (1848) officially ended the Mexican-American War (1846–1848) in February 1848. Despite the treaty, tensions between Mexico and the United States continued. A significant point of contention was the Mesilla Valley, which both nations claimed as their territory.

Mexico was also frustrated because Native American Indians were carrying out raids in the region (see Apache Wars). According to the Treaty of Guadalupe Hidalgo, the United States had agreed to protect Mexico from such attacks. However, when Mexico demanded financial compensation for the damages caused by the Indians, U.S. officials refused. They argued that while they had promised to protect Mexico, they had not agreed to pay for damages caused by any attacks.

The situation was escalated by private American citizens who illegally entered Mexico. Some of them tried to incite rebellion in hopes of securing more territory for the United States.

Dispute Over the Isthmus of Tehuantepec

The ongoing tensions between Mexico and the United States made it difficult for the U.S. to establish a southern route for a Transcontinental Railroad. The only feasible routes for the railroad went through Mexican territory.

In 1847, the United States tried to purchase the Isthmus of Tehuantepec. Located in southern Mexico, U.S. officials believed it could provide an alternative connection between the Atlantic and Pacific Oceans. However, Mexico had already given Don José de Garay the rights to develop colonies for Americans on the isthmus, using funds from the New Orleans Company. This was known as the Garay Project.

Mexican President Juan Ceballos became concerned that these American colonists might rebel, similar to the rebellion in Texas (See Texas Revolution Overview), and then be annexed by the United States (see Texas Annexation Overview). Because of this, he revoked the grant given to Garay, which upset U.S. investors who were hoping to profit from the Garay Project.

Tension in the Mesilla Valley

In 1853, Mexican officials forced American settlers out of the Mesilla Valley, a region that was claimed by both nations. When the United States failed to respond, Governor William Lane of New Mexico declared the Mesilla Valley to be part of U.S. territory.

Mexican President Antonio de Santa Anna responded by sending Mexican troops to occupy the valley. To calm the situation, U.S. President Franklin Pierce sent James Gadsden, the new U.S. Minister to Mexico, to negotiate with Santa Anna.

Secretary of State William Marcy gave Gadsden specific instructions for the negotiation: 

  1. Redefine the border to secure a route for a southern railroad.
  2. Negotiate the release of U.S. financial obligations related to protecting Mexico from Native American attacks.
  3. Settle monetary claims between the two countries regarding the Garay Project on the Isthmus of Tehuantepec.

Gadsden Negotiates with Santa Anna

James Gadsden met with Mexican President Antonio de Santa Anna on September 25, 1853, to negotiate a land purchase. President Franklin Pierce sent verbal instructions to Gadsden through Christopher Ward, an agent representing American investors involved who in the Garay Project.

President Pierce gave Gadsden the following options:

  1. Offering up to $50 million for acquiring Lower California and a large part of northern Mexico.
  2. Offering $15 million for a smaller area sufficient for a southern railroad route.

However, Ward misled Gadsden, telling him that President Pierce also wanted the Garay Proejct’s claims addressed in any treaty. This was not true, as President Pierce did not believe the government should interfere in matters between private companies and foreign governments.

Santa Anna refused to sell a large portion of Mexico, but he needed funds for military operations to suppress ongoing rebellions. As a result, Santa Anna and Gadsden signed a treaty on December 30, 1853. The key provisions of the agreement were:

  • The United States agreed to pay $15 million for 45,000 square miles of land south of the New Mexico Territory. 
  • The U.S. also assumed private American claims, including those related to the Garay Project.
  • The U.S. agreed to help prevent Indian raids along the Mexican border.
  • Mexico voided the U.S. financial responsibility for damages caused by Indian attacks.

Senate Revisions to the Treaty

Despite significant challenges arising from growing tensions between the northern and southern states in the U.S. (Sectionalism), the Senate ratified a revised treaty on April 25, 1854. The changes in the new treaty included:

  • Reducing the payment to Mexico from $15 million to $10 million.
  • Decreasing the size of the land purchased from 45,000 square miles to 29,670 square miles.
  • Removing any mention of Indian attacks and private claims.

President Franklin Pierce signed this revised treaty, and James Gadsden presented it to Santa Anna. Mexican President Santa Anna signed the treaty on June 8, 1854, finalizing the agreement.

The End of Westward Expansion

After the Gadsden Purchase, new tensions arose regarding the United States’ payment to Mexico. The treaty did not fully address the issues related to financial claims and border attacks, leading to continued disputes. Despite these unresolved issues, the treaty successfully established the southern border of the present-day United States.

At the time, many American officials believed that the United States would eventually expand further into Mexico. However, this did not occur, and the Gadsden Purchase marked the final major territorial acquisition in the contiguous United States.

The quest to expand from the East Coast to the West Coast was completed, ending Westward Expansion driven by Manifest Destiny.

Gadsden Purchase Vocabulary

These terms and definitions provide more context for students studying this entry about the Gadsden Purchase.


  • Juan Ceballos — The President of Mexico who revoked the grant for colonization on the Isthmus of Tehuantepec.
  • Don José de Garay — A Mexican investor who was granted the right to build colonies on the Isthmus of Tehuantepec.
  • William Lane — The Governor of New Mexico who declared the Mesilla Valley part of U.S. territory.


  • Atlantic Ocean — The eastern ocean that the Southern Transcontinental Railroad aimed to connect.
  • Isthmus of Tehuantepec — A narrow strip of land in southern Mexico considered for an alternative route connecting the Atlantic and Pacific Oceans.
  • Lower California — A region in Mexico that was part of the larger land deal proposed by the U.S.
  • Mesilla Valley — A disputed region claimed by both Mexico and the United States.
  • New Mexico — The U.S. territory whose governor declared the Mesilla Valley part of it.
  • Pacific Ocean — The western ocean that the Southern Transcontinental Railroad aimed to connect.
  • Southern Border — The boundary established by the Gadsden Purchase, marking the border between the United States and Mexico.


  • Mexican-American War — A conflict between the United States and Mexico from 1846 to 1848.
  • Native American Indian Attacks — Conflicts initially mentioned in the first treaty but removed in the revised version.
  • Mexican Rebellions — Internal conflicts in Mexico that Santa Anna needed funds to address. Some were driven by Private American Citizens to overthrow Mexican control in order to gain territory.
  • Texas Rebellion — A previous rebellion by American colonists in Texas that influenced Mexican fears of a similar uprising on the Isthmus of Tehuantepec.


  • Garay Project — A project involving American investors and the Isthmus of Tehuantepec.
  • New Orleans Company — The source of capital for developing colonies on the Isthmus of Tehuantepec.


  • Border Dispute — A disagreement over the exact location or management of a border.
  • Evicted — Forced to leave a property.
  • Financial Claims — Claims for money owed, typically related to damages or other obligations.
  • Policymakers — Individuals involved in the process of making policies or laws, particularly government officials.
  • Private American Claims — Financial claims by American citizens and investors, including those related to the Garay Project.
  • Private American Citizens — People from the United States who illegally entered Mexico and attempted to incite rebellions.
  • Ratified — Formally approved by the U.S. Senate.
  • Revoke — To take back or withdraw a previously granted right or privilege.
  • Southern Transcontinental Railroad — The intended railroad route that required the new land acquisition.
  • Tension — A state of strained relations or antagonism between countries or groups.
  • Territorial Acquisition — The process of acquiring land or territory through treaties, purchases, or other means.
  • Treaty of Guadalupe Hidalgo — The treaty that ended the Mexican-American War and outlined the obligations of the United States towards Mexico.
  • Verbal Instructions — Spoken instruction given by President Pierce to Gadsden through Ward.

Citation Information

The following information is provided for citations, including APA Style, Chicago Style, and MLA Style.

  • Article Title Gadsden Purchase
  • Date 1854–1854
  • Author
  • Keywords Gadsden Purchase
  • Website Name American History Central
  • Access Date June 21, 2024
  • Publisher R.Squared Communications, LLC
  • Original Published Date
  • Date of Last Update May 29, 2024