The Eugene McDermott Library was designated a federal depository library in 1972.  At the time, it was the only depository library in the then 32nd U.S. Congressional District.  It is a selective depository.

The Library was designated a Texas State depository in 1974.  In June of 2011, cuts to state funding necessitated severe curtailment of the program.

The document collections are supplemented by several microfiche and microfilm collections and online resources such as ProQuest Congressional.