April 19th marks the 250th anniversary of the battles of Lexington and Concord, the famous ‘shot heard “round the world.” The start of the American war of independence happened against a global backdrop of Britain, France and Spain jockeying for world dominance, with trade centered in the Caribbean and Gulf of Mexico. The World’s Carolyn Beeler explores what was going on around the globe in 1775 with Larrie Ferreiro, a professor at George Mason University and the author of “Brothers at Arms: American Independence and the Men of France and Spain Who Saved It.”