The first U.S. census of the area that became the State of Oklahoma was taken in 1900.
There was actually two census in 1900 covering the area that became Oklahoma: Indian Territory and Oklahoma Territory (see map: http://www.rootsweb.com/~okgenweb/maps/ok1900xp.gif ). Consequently- there are two 1900 Soundex of the area: microfilm series #T1082 for Indian Territory and series #T1066 for Oklahoma Territory. Order the film as for any "state"; by Soundex code. For those of you that are new to genealogy and do not know how to use the Soundex, then you are missing out on a vital resource! Go to http://www.rootsweb.com/~rwguide/lesson9.htm and LEARN HOW TO DO IT!
On the Soundex film for Indian Territory, you will see the "Indian Nation" listed instead of "County" that you will see on the regular state Soundex film. On the upper right corner you will see several boxes- including "Vol" (disregard); "ED" ("Enumeration Dist"); "sheet" (the hand-written number entered on the page); and "Line" (the printed line number on the left side of that page).
NOTE: the 1880 census Soundex for the states are not complete! It does NOT list every family living in the state- only those having children "under the age of 11".
After you identify the family on the 1900 Soundex, then you are ready to view the same record on actual census. The census record will give you the name, family status ("wife"; "son", etc), sex, race, month and year of birth, age (as at 1 June 1900), marital status, how many times married, how many years married to this spouse, how many children born to this mother, how many of these children now living, occupation, where this person was born (state or country), birthplace of father, birthplace of mother (etc). Now, wouldn't this information fill in a bunch of gaps in your family records? I know that the census records are not always correct nor perfect, but as genealogists, we should consider each and every resource, including the census!
Next you must locate what roll of microfilm that this family is shown on. You can view the AGLL ("American Genealogical Library") catalog on-line with Acrobat Reader. For the U.S. census catalog, go to http://www.heritagequest.com/catalog/USCensus.pdf . You should be aware that the 1900 Indian Territory census film (complete with descriptions on what nations and ED's it covers) is NOT listed in alphabetical sequence (listed after Wyoming), but the Oklahoma Territory census is in alphabetical order.
For the listing of the 1900 Indian Territory, click (left side) on
"1900", then scroll down (watch numbers at bottom of right side) to "page
137 of 389".