Very late today, but just in time to keep the series intact as Nebraska's official join date of July 1st, 2011 draws near.
Nebraska tried to join the Big Ten before, several times, in fact, although there seems to be some discrepancies regarding what years Nebraska attempted to join the Western Conference (before it was known as the Big Ten). Of course, up until this past year, who would have cared? It wasn't an issue - Nebraska had been a conference member with some of the old Big Eight teams back then - and no one could have guessed what happened a year ago would actually happen.
Nebraska's early attempts were turned down, interestingly enough, for some of the same reasons that were debated last year.
Both Nebraska and Notre Dame were not allowed to join the "Middle Western Big Nine" conference in 1902. No explanation was given at the time. The same happened again in 1903.
In 1913, Nebraska and Notre Dame were denied membership again, because the "Big Nine" feared that if they allowed the two schools to join that expansion would continue, apparently creating a super conference that would engulf the entire world (or something like that).
Then, in 1925, Nebraska and Michigan State were rejected, and Nebraska stayed with the Missouri Valley Intercollegiate Athletic Association. Three years later, in 1928, Nebraska, Iowa State, Kansas, Kansas State, Missouri and Oklahoma would form the Missouri Valley Conference - the forerunner to the Big Six, and later the Big Eight.