The New Yorker looks at the GSEs
. One tidbit:
It wasn’t until 1968 that Fannie was privatized....The main reason for the change was surprisingly mundane: accounting. At the time, Lyndon Johnson was concerned about the effect of the Vietnam War on the federal budget. Making Fannie Mae private moved its liabilities off the government’s books, even if, as the recent crisis made clear, the U.S. was still responsible for those debts. It was a bit like what Enron did thirty years later, when it used “special-purpose entities” to move liabilities off its balance sheet.