Strategically located at the crossroads of Europe, Asia, the Middle East, and Africa, Greece has a thriving shipping industry. Dating back to ancient times, its fleet and ports always were key elements of its economic activity. During the 1960s, the size of the Greek fleet nearly doubled, primarily through investment by shipping magnates such as Aristotle Onassis and Stavros Niarchos. The basis of the modern Greek maritime industry was formed after World War II when Greek shipping businessmen were able to amass surplus ships sold to them by the U.S. government through the Ship Sales Act of the 1940s.