I like your avatar. I have not thought about Blue Oyster Cult band in a long time. Go Go Godzillaaaaaaaaa....
Correct and made mandatory on all US coins in 1908. (The Indian Head nickel design was technically illegal since it didn't have the motto mandated by law on it.) It was made mandatory on the currency in 1955 and first appeared in 1957 on the 1935 G one dollar silver certificates. (Not including the 1886 five dollar silver certificates that had five Morgan dollars pictured on the back that showed the motto.)
Everyone who replied "1864" is technically wrong. Some 1863 pattern coins had it. Like this one: http://ep.yimg.com/ca/I/uspatterns_2270_82366309