In 1888, the large number of settlers coming to Western Nebraska resulted in the partitioning of Cheyenne County. The western third became Kimball, Scotts Bluff and Banner Counties. The last of these was name by citizens who declared that it would become the "banner county" of the state, and "the brightest star in the constellation of Nebraska counties".

About 60% of Banner County is given over to farming: chiefly winter wheat and rangeland, but also corn, beans, sugar beets, botatoes, sunflowers, rapeseed and millet. Oil was discovered in Banner County in 1919; but the deposits were too deep to be commercially viable. Production of oil in the county began in 1951, and peaked in 1960, when 7,000,000 barrels was produced from 397 wells. By 2009, the number of weels had fannel to about 200; but new discoveries in Weld County, COlorado have prompted interest in exploring the Niobrara shale, which lies beneath western Nebraska, northeastern Colorado and southeastern Wyoming. A 2010 sale of oil leases yielded record prices in Banner county.

The Banner County Wind Farm is a proposal by the Chicago based Midwest Wind Energy company to construct a $60 million wind farm in Banner County. The 60,000 to 100,000 acre wind farm will have 600 to 800 turbines and peak capacity of 2,000 megawatts. The wind farm was intentionally designed to be big in order to force the construction of improved transmission lines. It is expected that it will take 10 years to complete the project. The wind farm would be the largest in Nebraska.

The 2009 estimated population of Banner County is 647. The county is 746 square miles and is located between Kimball County to the south and Scotts Bluff County to the north. Highway 71, a major north-south transportation route which intersects with I-80 to the south of the county runs through the county.

Harrisburg is the County Seat of Nebraska. The estimated population as of 2009 was 66. The median home cost in Harrisburg is $49,700. Home appreciation the last year has been 2.19%. The unemployment rate in Harrisburg is 2.9% (U.S. avg. in December 2009 was 9.4%.

Banner County Public Schools are located in Harrisburg, NE. BCPS spend $7,660 per student. The average school expenditure in the U.. is $5678.00. There are about 9.4 students per teacher in Harrisburg.