What's the difference between i.e. and e.g.?
"U.S. dollar bill," 1862, so called from the time of their introduction, from green (adj.) + back (n.); bank paper money printed in green ink had been called this since 1778 (as opposed to redbacks, etc.).
A dollar bill
[1870+; said to have been coined by Salmon P Chase, who died in 1873]