overt resistance to the draft, especially in Catholic areas. The draft riot in New York City in July 1863 involved Irish immigrants who had been signed up as citizens to swell the vote of the city's Democratic political machine, not realizing it made them liable for the draft. Of the 168,649 men procured for the Union through the draft, 117,986 were substitutes, leaving only 50,663 who had their services conscripted. In both the North and South, the draft laws were highly unpopular. In the North, some 120,000 men evaded conscription, many of them fleeing to Canada, and another 280,000 soldiers deserted during the war. At least 100,000 Southerners deserted, or about 10 percent; Southern desertion was high because, according to one historian writing in 1991, the highly localized Southern identity meant that many Southern men had little investment in the outcome of the war, with individual soldiers caring more about the fate of their local area than any grand ideal. In the North, "bounty jumpers" enlisted to get the generous bonus, deserted, then went back to a second recruiting station under a different name to sign up again for a second bonus; 141 were caught and executed. From a tiny frontier force in 1860, the Union and Confederate armies had grown into the "largest and most efficient armies in the world" within a few years. Some European observers at the time dismissed them as amateur and unprofessional, but historian John Keegan concluded that each outmatched the French, Prussian, and Russian armies of the time, and without the Atlantic, would have threatened any of them with defeat. Prisoners At the start of the Civil War, a system of paroles operated. Captives agreed not to fight until they were officially exchanged. Meanwhile, they were held in camps run by their army. They were paid, but they were not allowed to perform any military duties. The system of exchanges collapsed in 1863 when the Confederacy refused to exchange black prisoners. After that, about 56,000 of the 409,000 POWs died in prisons during the war, accounting for nearly 10 percent of the conflict's fatalities. Women Historian Elizabeth D. Leonard writes that, according to various estimates, between five hundred and one thousand women enlisted as soldiers on both sides of the war, disguised as men. Women also served as spies, resistance activists, nurses, and hospital personnel. Women served on the Union hospital ship Red Rover