The Library of Congress has a lot of documents, books and manuscripts on their website. One manuscript of particular interest to this group is the title in my subject line, written by Mexican lawyer, Matias de la Mota Padilla in 1742. It is hand-written, but very legible. It contains a lot of names of people and places dating from the Conquest to 1742 in Nueva Galicia. The link to the Library of Congress is already in the links section. You can find the book by clicking on "Collections" and then browsing through the list of Selections from the National Library of Spain.
Maria Cortez