Today In History: What Happened On Sept 15

★Independence Day of Costa Rica, ★Independence Day of El Salvador, ★National Engineers’ Day, ★International Day of Democracy, ★1254: Birth of world traveler Marco Polo, ★1861: Birth of India’s leading engineer Mokshagundam Visvesvaraya, ★1876: Birth of renowned Bengali writer Sarat Chandra Chattopadhyay, and ★1970: Birth of film actress Ramya Krishna.