protection of Washington, 255;
passage of Massachusetts troops through Baltimore, 256-258;
proclamation of blockade, 283;
naval situation, 283, 284;
second call for volunteers, army increased, 291;
military episodes of 1861, 298, 299;
campaign of Bull Run, 300-302;
character and organization of Northern armies, 304-308;
McClellan commander-in-chief, 310;
civilian officers in, 319;