It is the excessive use of credit. The shares trading system crash of 1929 touched off a chain of occasions that dove the United States into its longest, most profound monetary emergency in its history. It is awfully shortsighted to see money markets crash as the single reason for the Great Depression. A solid economy can recuperate from such a compression.
Villa's dominance in northern Mexico was broken in 1915 through a series of defeats he suffered at Celaya and Agua Prieta at the hands of Álvaro Obregón and Plutarco Elías Calles. After Villa's famous raid on Columbus, New Mexico, in 1916, U.S. Army General John J. Pershing tried unsuccessfully to capture Villa in a nine-month pursuit that ended when the United States entered into World War I and Pershing was called back. Villa retired in 1920 and was given a large estate, which he turned into a "military colony" for his former soldiers
so A
ANSWER: the map can be a primary or secondary source. If a map was produced as immediate evidence of an area, then it is a primary source. If the map is just a symbolic depiction of a space then it is a secondary source.
