The New Mexico Territory<span>, which included the areas which became the modern </span>U.S. states<span> of </span>New Mexico<span> and </span>Arizona<span> as well as the southern part of </span>Nevada<span>, played a role in the </span>Trans-Mississippi Theater<span> of the </span>American Civil War<span>. Both </span>Confederate<span> and </span>Union governments claimed ownership and territorial rights over it. <span>The first proposal dates from a conference held in </span>Tucson<span> that convened on August 29, 1856. The conference issued a petition to the U.S. Congress, signed by 256 people, requesting organization of the territory and elected </span>Nathan P. Cooke<span> as the territorial delegate to Congress.</span>
