[2] The Dakota Territory legislature created Nelson County on March 2, 1883, with areas annexed from Foster, Grand Forks and Ramsey counties, and with some previously unorganized area.

It was not organized at that time, but was attached to Grand Forks County for administrative and judicial purposes.

[3][4] The county terrain consists of rolling hills dotted with lakes and ponds.

[5] The terrain slopes to the south and east, with its highest point near the midpoint of its north boundary line, at 1,545 ft (471 m) ASL.

Nelson County voters have slightly favored Republicans for the past several decades.