structural:reformatting, structural:expansion, stylistic:style_transfer
Mexico era

As part of New Spain, the province of New Mexico became part of the First Mexican Empire in 1821 following the Mexican War of Independence. Upon its secession from Mexico in 1836, the Republic of Texas claimed the portion east of the Rio Grande, based on the erroneous assumption that the older Hispanic settlements of the upper Rio Grande were the same as the newly established Mexican settlements of Texas. The Texan Santa Fe Expedition was launched to seize the contested territory but failed with the capture and imprisonment of the entire army by the Hispanic New Mexico militia.