Mexican Americans were a minority. They seem to be few in number than their american counterparts, also new mexico is a territory and not a state. Generally In-order to get the focus of the Federal Government to a particular state or territory, the government should own the land with dense population and the land should be home to some naturally found resources and development, where the Federal government did not have to spend a huge money for development. Unfortunately the New Mexico territory doesn't have all these to attract any interests from the Federal Government.