The H.15 historical data is available through the Data Download Program at:
http://www.federalreserve.gov/datadownload/Build.aspx?rel=H15

This series, H15/H15/RIFSGFSY01_N.M, is available at:
http://www.federalreserve.gov/datadownload/Output.aspx?rel=H15&series=72e4e25bdd1f5ea0a29031e7b3b476a8&lastObs=&from=&to=&filetype=csv&label=include&layout=seriescolumn