Dayton, O. City and seat of justice of Montgomery co. On the Great Miami River, at the mouth of Mad River, 50 miles N. from Cincinnati, and 68 W. by S. from Columbus. The Miami Canal from Cincinnati to Lake Erie passes through this place. Population in 1810, 383; 1820,1139; 1830,2954; 1840, 6067; 1850, 10,996. Dayton is one of the largest places in the interior of the state. There is a large water power within its corporate limits, and a still greater within the immediate vicinity.

Yorktown, the seat of justice, is on York River, 11 miles from its mouth, 33 from Norfolk, and 70 from Richmond. It was established by law in 1705, and was once a nourishing village, and had considerable commerce. There are now only about 40 dwellings, many of which are dilapidated and fast going to decay. The Swan tavern, in this town, is said to be the oldest in Virginia.

YORK was one of the eight original counties into which Virginia was divided in 1634. Chesapeake Bay bounds it on the east, and York River on the NE. It is 30 miles long, with a mean width of 5 miles. Population in 1840, 4,720.

Fairfax Court House is near the centre of the county, 21 miles from Washington City; it contains the county buildings, and about 200 inhabitants.

FAIRFAX  was formed in 1742, from Prince William, and named after Lord Fairfax, the proprietor of " the Northerly Neck." The part of Virginia included in the District of Columbia was formed from Fairfax. The county is watered by the Potomac and the Occoquan, and their branches. Pop., whites 5,469, slaves 3,453, free colored 448; total, 9,370.

Lafayette, in the north part of the county, at the junction of the two forks of the Roanoke, contains a Methodist church, and about 45 dwellings.

Blacksburg, 9 miles north of the C. H., contains 1 Presbyterian and 1 Methodist church, and a population of about 250.

Christiansburg, the county-seat, lies 203 miles southwesterly from Richmond, 46 miles from Fincastle, and 47 from Wytheville, on the main stage-road from Richmond to Nashville, Tenn. It was established by law Oct. 10, 1792, and the following gentlemen appointed trustees: Christian Snido, Byrd Smith, James Barnett, Hugh Crockett, Samuel Eason, Joseph Cloyd, John Preston, James Charlton, and James Craig. It contains 4 stores, 1 Presbyterian and 1 Methodist church, and a population of about 400.

MONTGOMERY was formed in 1776, from Fincastle county,* and named from Gen. Montgomery: it is about 23 miles long, and 22 broad. New River runs on its southwestern border, which, with the head-waters of Roanoke River, drain the county. The lace of the county is broken and mountainous, though the streams are bordered with excellent soil, which yield heavy crops of corn and wheat. Pop. in 1840, whites 5,825, slaves 1,473, free colored 87; total, 7,405.