By 1913, there were more than 1,400 mestizos with American parentage, the product of the nearly 8,000 Americans living in the Philippines. 15% of the children of Americans who settled in the Philippines were orphans. Prior to World War II, Americans were not prevalent in the Philippines, most living in enclaves, particularly around Fort Santiago; one term for those who settled in the Philippines was "Manila Americans". By 1939, 8,709 Americans were in the Philippines, primarily in Manila, and of whom only 4,022 were working age and employed. The Japanese invasion of the Philippines brought about an abrupt end to the distinctions of race, due to the external threat caused by the invasion.