Admitted to the Union on March 1, 1867 as the 37th state. Nebraska became a territory in 1854.
- 1860 – 1940 federal censuses extant for all counties except for 1890.
| Adams | Antelope | Arthur | Banner |
| Blaine | Boone | Box Butte | Boyd |
| Brown | Buffalo | Burt | Butler |
| Cass | Cedar | Chase | Cherry |
| Cheyenne | Clay | Colfax | Cuming |
| Custer | Dakota | Dawes | Dawson |
| Deuel | Dixon | Dodge | Douglas |
| Dundy | Fillmore | Franklin | Frontier |
| Furnas | Gage | Garden | Garfield |
| Gosper | Grant | Greeley | Hall |
| Hamilton | Harlan | Hayes | Hitchcock |
| Holt | Hooker | Howard | Jefferson |
| Johnson | Kearney | Keith | Keya Paha |
| Kimball | Knox | Lancaster | Lincoln |
| Logan | Loup | McPherson | Madison |
| Merrick | Morrill | Nance | Nemaha |
| Nuckolls | Otoe | Pawnee | Perkins |
| Phelps | Pierce | Platte | Polk |
| Red Willow | Richardson | Rock | Saline |
| Sarpy | Saunders | Scotts Bluff | Seward |
| Sheridan | Sherman | Sioux | Stanton |
| Thayer | Thomas | Thurston | Valley |
| Washington | Wayne | Webster | Wheeler |
| York |