Thousands of documents pertaining to Joe Biden’s nearly 40-year career in the U.S. Senate are still unavailable to the public after one of the preliminary release deadlines agreed to by the former vice president passed on Tuesday.

The documents, which purportedly fill 1,875 boxes and include 415 gigabytes of electronic records spanning Biden’s time in Congress between 1973 through 2009, were to be made public on Dec. 31, 2019, according to an agreement the former vice president entered into with the University of Delaware in 2011 upon donating his papers to the institution.

Those parameters, however, were changed on April 24—the day before Biden declared his 2020 campaign—when the university announced the trove of documents would now be made public on Dec. 31 or “two years” after the former vice president “retires from public life.” At the time, the university provided no definition for what it considered “public life,” leaving open the final date for release.

Included among the documents are “committee reports, drafts of legislation,” and personal correspondance between Biden and his colleagues. Some of the records are likely to be controversial, especially those detailing the former vice president’s early work alongside southern segregationists to oppose busing to integrate public schools.

The issue reared its head in June 2019, when Biden praised the “civility” of two such allies, the late-Sens. James Eastland (D-MS) and Herman Talmadge (D-GA), while touting his ability to forge bipartisan consensus.

I was in a caucus with James O. Eastland,” the former vice president told donors at a fundraiser in New York at the time. “He never called me boy, he always called me son.”

“Well guess what?” Biden continued. “At least there was some civility. We got things done. We didn’t agree on much of anything. We got things done. We got it finished. But today you look at the other side and you’re the enemy. Not the opposition, the enemy. We don’t talk to each other anymore.”