Most people today don't know this, but from 1863-1935, local National Banks could issue their own banknotes, which were legal tender anywhere in the United States.
Here are some examples of U.S. currency produced by the two National Banks in Covina in the early years of the 20th century. (The first two are the old, large "horse blanket" banknotes; the third is the same size as our bills are today.)
$5 note, Series of 1882, Charter date 1901. Portrait depicts the late President James Garfield. Click image to enlarge.
$10 note, Series of 1902, Charter date 1921. Portrait depicts the late President William McKinley. Click image to enlarge.
$20 note, Covina National Bank, Series of 1929. Image courtesy seller jscabani1988 on eBay.
Below are some historical photos of Covina's two chartered National Banks.