A Mexican cavarly unit attacked a group of U.S. soldiers in a disputed zone who were under the command of General Zachary Taylor. This is what sparked the Mexcian-American War and the United States had a "manifest destiny" to spread across the continent to the Pacific Ocean. The U.S. won the war, gaining control over California, Utah, Nevada, Arizona and New Mexico.
the correct answer is actually : Personal contact with Christians and Jews
Vatican City, located in Rome.
