[3] It was named for Norman B. Campbell, a Dakota Territory legislator in 1873 and son of General Charles T.

[5] By 1911 the communities of Artas, Herreid and Pollock had the largest populations because they were located on a branch of the Soo Line.

The Missouri River flows southward along the county's west boundary line.

The county terrain consists of semi-arid low rolling hills, a portion of which is dedicated to agriculture.

[7] The terrain slopes to the south and east, with its highest point occurring on the county's north boundary line, toward the NE corner: 2,060 ft (630 m).

The Reformed Church in the United States, the Wisconsin Evangelical Lutheran Synod, and the North American Baptist Conference were also represented with lesser numbers.

It has only once been carried by a Democratic presidential candidate, during Franklin D. Roosevelt’s landslide victory of 1932.

Nonetheless, in the following election when FDR gained an even more emphatic victory by carrying forty-six of forty-eight states, his Republican opponent Alf Landon carried Campbell County by twenty-five percentage points, making the county Landon's second-strongest in the Plains States (behind Brown County in his home state).