Partial Source: Pwinsider.com
While it is not known when the deal for the video library was finalized, WWE lists the Global Wrestling Federation library when showcasing their video library in the History of the WWE DVD documentary. Global is the Dallas, Texas promotion that ran for several years in the early 1990s and aired on ESPN and has been recently airing on ESPN Classic.
WWE has been using some of the footage on Classics OnDemand, usually matches involving Booker T for the last year, but it was never made clear that they had acquired the library.
The documentary also listed that WWE owned Georgia Championship Wrestling material.