I would check out the public papers of the presidents, the US Government Manual, and congressional records. These will be in any law library. CSPAN has a huge library of media as well. Also I will second the Robert Caro suggestion. His books are extremely long, but often a chapter can be read independently. I personally recommend the chapter "1 mile" from The Power Broker and "Lyndon Johnson and the Liberal" from Master of the Senate. I am not especially well placed to answer this question; just a fellowtraveler pursuing the same question.
I would check out the public papers of the presidents, the US Government Manual, and congressional records. These will be in any law library. CSPAN has a huge library of media as well. Also I will second the Robert Caro suggestion. His books are extremely long, but often a chapter can be read independently. I personally recommend the chapter "1 mile" from The Power Broker and "Lyndon Johnson and the Liberal" from Master of the Senate. I am not especially well placed to answer this question; just a fellowtraveler pursuing the same question.