Which Russian-born gangster, a childhood friend and partner of Bugsy Siegel, became known as the "Mob's Accountant"?

Which German engineer had perfected his alternative to the Otto gasoline engine by 1897? Which American writer settled in France in 1903, where she was later joined by Alice B. Toklas? By 1905, college football had become so violent that which U.S. president urged rule changes? Which merchant's company owned hundreds of stores bearing his name across the U.S. by 1912? By age 25, J. Robert Oppenheimer had published many papers in which then-new field of physics? Artem Mikoyan and Mikhail Gurevich produced the first of which Soviet fighter planes by 1940? By 1942, FDR had appointed seven new members to which body, getting the "packing" he wanted after his 1937 plan failed? Which American astronomer discovered Pluto in 1930 at Lowell Observatory?