"Londonderry, a county of Ireland, province of Ulster, 40 m. long and 31 broad, bounded W by Donegal, N by the ocean, S and SW by Tyrone, and E by Antrim, containing 511,688 English acres, divided into 31 parishes. It sends 4 members to parliament. 1/4 seems to be bleak mountains and glens, and 1/2 of the remainder is mountainous. Potatoes are the principal crop; and in some parts oats, barley, flax, and rye, and some wheat are cultivated. Chief rivers, the Foyle or Green river, the Bann or White river, the Faughan, and the Roe. The linen manufacture flourishes through every part of the county. Pop. 194,099."
[From The New London Gazetteer (1826)]