[3] The county was named for Abraham Lincoln, 16th President of the United States.

[1] Lincoln County is included in the Sioux Falls, SD, Metropolitan Statistical Area.

The Big Sioux River flows south-southeastward along the east line of Lincoln County.

[4] The terrain slopes to the southeast, and drops off to the river valley along its east edge.

In terms of ancestry, 47.1% were German, 20.9% were Norwegian, 11.7% were Irish, 7.2% were Dutch, 5.2% were English, and 3.9% were American.

Source:[4] Lincoln County voters have been reliably Republican for decades.

[16] In 1924 the county voted for independent candidate LaFollete[17] who was nominated by the progressive party but ran without a label in South Dakota.