Meanwhile the Confederate forces were getting uncomfortably close to Washington. From the White House a secession flag could be seen flying at Alexandria, which was occupied by a small pro-secession garrison. There was fear lest that party would occupy Arlington Heights, across from Washington, and thence pour shot and shell into the city. At two o'clock on the morning of May 24th, eight regiments crossed the Potomac and took possession of these hills as far south as Alexandria, and fortified them. The latter place was entered by Colonel Ellsworth with his famous New York Zouaves. No resistance was made, as the Confederates had retired, but Ellsworth was brutally assassinated while hauling down the secession flag. [Illustration: Portrait.] Captain Nathaniel Lyon. Upon the secession of Virginia the Confederate capital was removed to Richmond. The main armies of both sides were now encamped on Old Dominion soil, and at no great distance apart; but the commanders were busy drilling their raw troops, so that for a time only trifling engagements occurred. General Butler, with a considerable body of men, was occupying Fortress Monroe, at the mouth of the James River. June 10th, an expedition sent by him against the Confederates at Big Bethel, some twelve miles distant, was repulsed after a spirited attack, with a total loss of sixty-eight. A week later an Ohio regiment took the cars to make a reconnoissance toward Vienna, a village not far south of Washington. They were surprised by Confederates, who placed two guns on the track and fired on the train as it came around a curve. The Ohioans sprang to the ground, and after some fighting drove their opponents back. All this time both North and South were struggling for possession of the neutral States. Governor Jackson, of Missouri, was straining every nerve to force his State into secession. Early in May two or three regiments of militia were got together and drilled in a camp near St. Louis. Cannon were sent by President Davis, boxed up and marked "marble." Captain Lyon, of the regular army, who held the St. Louis arsenal with a few companies, reconnoitred the secessionist camp in female dress. The next day, May 10th, assisted by local militia, he suddenly surrounded it and took 1,200 prisoners. A month later he embarked some soldiers on three swift steamers, sailed up the Missouri to Jefferson City, the state capital, and raised the Union flag once more over the State House. Governor Jackson fled. During the next month all the armed disunionists were driven into the southwestern part of the State. [Illustration: Portrait.] General John C. Fremont.