The oldest officially mandated ETD that we have in D-Scholarship is from 2002. Several alumni have had their works digitized and placed within D-Scholarship including a work from 1934. Since Pitt faculty, staff, and students can deposit their work at any time, we also have much older documents, including one article from 1950. 

You can explore by going to D-Scholarship and selecting "Year" from the "Browse By" menu in the middle of the page. You can also browse by the document type to see the Pitt ETDs and other types of documents in D-Scholarship, as well as by school so that you can narrow down your view to just the materials in your area.