Bank credit is a category on the asset side of a bank's balance sheet. It is the sum of (i) Treasury, Agency, and other securities, and (ii) loans and leases. In December 2008, bank credit comprised 81 percent of total assets of commercial banks in the United States. Additional information can be found in the Federal Reserve's H.8 release.
See even more long-term Bank Credit of All Commercial Banks charts and historical data from FRED (Federal Reserve Economic Data), the St. Louis Fed Research Department's database of more than 20,000 U.S. economic time series.