We should only be so proud...straight from our official school website until they pulled it down:https://www.olemiss.edu/conf/welcometable/whyOM.html
Here's the archive: WHY OM?
"In the early decades of the twentieth century, a cadre of New South boosters
lobbied for reconciliation with the North in an effort to propel economic
advancement in the still-crippled region. It has been noted that one of the best
creations of the New South was the Old South, a suggestion that reflects those
New South boosters' attempts to mitigate their supplication of the assistance of
the North by hearkening back to a nostalgic, if illusory, "moonlight and magnolia"
time under slavery. During this time period, the university became known as
"Ole Miss," a moniker used by slaves to describe the wife of the plantation owner.

In 1948, on the heels of his own presidential initiative on race, President Harry
Truman desegregated the armed forces. In addition, he followed the recommendation
of his civil rights commission and added a civil rights plank to the Democratic
Platform for that year. In response to this addition, the entire delegation from
Mississippi and half of the delegation from Alabama walked out of the Democratic
Convention. They formed a new party, the Dixiecrats, and ran Strom Thurmond from
South Carolina as their presidential candidate. In the wake of this rebellion
against recognition of civil rights as a priority, students at the university
rallied behind their state's politicians, unfurling the Confederate battle flag put
away long before. Thus a new "tradition" began."

Where did ole miss originate?