🠈  Gadsden Purchase  🠊

The bulk of land in present day Arizona was acquired by the United States after the Mexican American War with the Treaty of Guadalupe Hildago. The area was considered part of the New Mexico Territory.

Ambiguously defined borders and disputes about slavery prevented New Mexico from becoming a state in the 1850s allowing for a redrawing of borders.

Gadsen Flag courtesy of Wikicommons

James Gadsden (1788 – 1858) was the grandson of Revolutionary War Hero Christopher Gadsden. The family is the namesake of the Gadsden Flag which bears the slogan "Don't Tread on Me." James Gadsden had served under General Andrew Jackson during the War of 1812. Andrew Jackson, the founder of the Democratic Party, became president in 1828.

James Gadsden star rose in the business world and he became president of the South Carolina Railroad in the 1840s. After the Mexican American War, Southern Railroads became interested in constructing a Transcontinental Railroad through the Southern US.

Surveyors concluded that a route through the mountains of the Northern New Mexico territory would be challenging and wanted to keep the line as far south as possible to keep it it southern control.

Negotiations over the Gadsden Purchase began with a desire to build a railroad through the Mesilla Valley.

Santa Anna had regained his position as President of Mexico. He needed money to rebuild the Mexican Army and desired assistance from the United States in addressing border raids by Comanche and Apache tribes in Northern Mexico.

The Gadsden Purchase was negotiated on December 30, 1853. It was ratified by Congress on April 25, 1854 and signed by President Franklin Pierce. The treatise acquired 29,670-square miles of land for $10 million dollars and a promise to stop Indian raids. The treatise included the Mesilla Valley (in New Mexico) and lands south of the Gila River in Arizona; thus establishing the present day border between the US and Mexico.

Confederate Arizona

As mentioned, the Democratic Party of the 1850s was pro-slavery. President Franklin Pierce and his Secretary of War Jefferson Davis wanted to extend the institution of slavery across the American West. Although against slavery, the Democratic Senator Stephen Douglas believed in self-determination and proposed the Kansas-Nebraska Act that would allow territories to choose their position on slavery.

Some Native American Tribes and some Mexicans practiced varying degrees of slavery. Mexican laws allowed enslavement of Indians, but excluded enslavement of blacks. Other groups in the territory opposed slavery.

In 1854, Stephen Douglas and Franklin Pierce passed the Kansas-Nebraska act. This act opened the flood gates on the issue of slavery in the West and led to a conflict called "Bleeding Kansas" in which political forces on both sides of the issue rushed into Kansas to determine the fate of the territory.

In 1854, Free Soilers and anti-slavery Whigs formed the Republican Party to oppose the expansion of slavery.

The election of Abraham Lincoln (a Republican) in 1860 incited the Democratic South to secede from the Union leading to the Civil War.

In March of 1862, Confederate forces defeated Union forces in the Battle of Mesilla in New Mexico. The Confederates declared the southern half of the New Mexico Territory to be "Confederate Arizona."

Confederates hoped to extend their claims but were pushed back by the Union after the Battle of Glorieta Pass. The Confederacy continued to claim Southern Arizona through the end of the Civil War.

Meanwhile, mining interests in Ohio wanted to develop the minerals in the Western half of the New Mexico Territory. James Ashley of Ohio proposed the "Arizona Organic Act" which carved the Arizona Territory from the New Mexico Territory. This act, signed into Law by Lincoln on February 24, 1863, established the current border between New Mexico and Arizona. The act abolished slavery in the Arizona Territory.


The Gadsden Purchase was inspired by pro-slavery forces hoping to create a Southern transcontinental railroad. This purchase brought Tucson and Yuma into the United States. During the Civil War, anti-slavery forces broke New Mexico in half and set the border between Arizona and New Mexico Border.


  1. Wikipedia - Gadsden Purchase (Drawn 3/20/2017)
  2. Wikipedia - Confederate Arizona (Drawn 3/20/2017)
  3. Wikipedia - Arizona Organic Act (Drawn 3/20/2017)

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