In 1846 during the Mexican–American War, the town was occupied by the Texas Rangers. After the war, the Treaty of Guadalupe-Hidalgo ceded the land to the United States. A referendum was taken in the town, which voted to petition the American military government in charge of the area to return the town to Mexico. When this petition was rejected, many who had been in the area for generations, moved across the river into Mexican territory, where they founded Nuevo Laredo. Many others, especially original land grantees on the north side of the Rio Grande remained, becoming Texans in the process. In 1849, the United States Army set up Fort McIntosh (originally Camp Crawford). Laredo was rechartered as a city in 1852.