The first settlements in the Nebraska Territory were along the Missouri River, the east border of what would, in 1867, become the state of Nebraska. Therefore, if you have ancestors who were in Nebraska early, begin looking at that area along the Missouri River.
Washington County, which is along the Missouri River, was an original county formed in 1854. It was one of the eight original counties proclaimed by acting Governor Thomas B. Cuming. Over time there were three different county seats ... Fort Calhoun, DeSoto and finally Blair which is the current county seat.
To study more about the history of Washington County, I suggest checking out the Washington County Historical Association's web page. You will find links and a good deal of information. Perhaps a trip to their museum should be put on your schedule.
There are some useful web pages on Internet that pertain to genealogical research in Washington County. Be sure to check out the Genealogy Trails History Group for Washington County. You will find online data, such as marriages for 1856-1898 and the 1927 school souvenir book.
The Washington County Genealogical Society's web page has useful maps and information on townships plus cemeteries. They also have suggestions for furthering your research and joining their society.
Be sure to visit the web page of the Blair Public Library. If you are visiting the area, they have local and family histories, cemetery records, death and marriage information, plus the Blair newspaper on microfilm.
At home on your computer, you can search the Blair City Cemetery Burials. You can also search the entire county for burials. The Washington County Genealogical Society link has an excellent map and listing of the cemeteries.
There is much more, so start snooping through Washington County and see what you can find. Have fun!