A liberty bond was a war bond that was sold in the United States to support the allied cause in World War I. Subscribing to the bonds became a symbol of patriotic duty in the United States.
There were four issues of Liberty Bonds
1) April 24, 1917 Emergency Loan Act authorizes issue of 1.9 billion in bonds at 3.5 percent.
2) October 1,1917 Second Liberty Loan offers 3.8 billion in bonds at 3 percent.
3) April 5,1918 Third Liberty Loan offers 4.1 billion in bonds at 4.15 percent.
4) September 28,1918 Fourth Liberty Loan offers 6.9 billion in bonds at 4.25 percent.
If bond traders didn't sell enough bonds they were looked at as "unpatriotic". The bond of Governs of New York stock exchange conducted an investigation of brokerage firms who sold below par to determine if "pro-German influences" were at work.
Liberty bonds are still used. Liberty bonds were issued after the September 11 terrorist attacks to finance the rebuilding of the areas affected.
“Liberty Bond.” Wikipedia, Wikimedia Foundation, 22 Nov. 2017, en.wikipedia.org/wiki/Liberty_bond.