In the United States, repos have been used from as early as 1917 when wartime taxes made older forms of lending less attractive. At first, repos were used just by the Federal Reserve to lend to other banks, but the practice soon spread to other market participants. The use of repos expanded in the 1920s, fell away through the Great Depression and WWII, then expanded once again in the 1950s, enjoying rapid growth in the 1970s and 1980s in part due to computer technology.