Final answer:
Before the Treaty of Guadalupe Hidalgo, North America's map was different, with Mexico controlling large territories now within the United States. This changed after the 1848 treaty, which ended the Mexican-American War and shifted major territorial lines.
Step-by-step explanation:
Prior to the Treaty of Guadalupe Hidalgo, the map of North America looked quite different. This treaty, which ended the Mexican-American War in 1848, resulted in Mexico ceding a large amount of territory to the United States. This included modern-day states such as California, Nevada, Utah, most of Arizona, half of New Mexico, parts of Oklahoma, Kansas, Colorado, and Wyoming. Therefore, before this treaty, these territories were under Mexican control, and the boundary of the United States was up to what is now known as Texas to the south, and up to the Pacific Northwest region in the west.
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