Answer

Go to the NYU Business Library's Economics & Statistics page

Finaeon specializes in historical financial data from 1200 to the present and  Data includes total returns, US Stocks, fixed income, equity and economic data.  Search for yield data to analyze. 

Use Bloomberg Type YCRV and press <GO> for evaluating yield curves.  The Library's Bloomberg stations are located on the 5th floor of Bobst Library. 

FRED, from the St. Louis Federal Reserve Board, offers several series for yield curve analysis. FRED contains 816,000 US and international time series from 107 sources.