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/discontinued/H1.RIFLGFY10P_N.M, is available at:
http://www.federalreserve.gov/datadownload/Output.aspx?rel=H15&series=ecfc3b293770c15b53cd017ab59d5069&lastObs=&from=&to=&filetype=csv&label=include&layout=seriescolumn