Increasing tensions between the United States and Mexico over their shared border culminates in war! The Treaty of Guadalupe Hidalgo establishes the border at the Rio Grande and Mexico cedes 55% of its northern territory, continuing the United States’ expansion westward. Read more about it!
The information in this guide focuses on primary source materials found in the digitized historic newspapers from the digital collection Chronicling America.
The timeline below highlights important dates related to this topic and a section of this guide provides some suggested search strategies for further research in the collection.
Texas gains independence from Mexico.
December 29, 1845
Texas becomes the 28th state in the Union.
May 11, 1846
Disputing between US and Mexico over location of Texas border.
May 12, 1846
Ongoing aggression between US and Mexico.
May 15, 1846
The United States declares war on Mexico.
April 3, 1847
General Scott lands at Veracruz.
April 8, 1847
US troops under General Taylor win the Battle of Buena Vista.
February 2, 1848
Nicholas Trist and Mexican officials sign Treaty of Guadalupe Hidalgo.
March 10, 1848
Congress ratifies the Treaty of Guadalupe Hidalgo.