Hemp has been cultivated by many civilizations over the course of 12,000 years. Archaeologically dated to the Neolithic Age (in China), the classical Greek historian Herodotus reported (around 480 B.C.E. or so) that the Scythians inhaled vapors of the smoke for pleasurable recreation.
Textile usage did not seem to emerge until the Iron Age.
Palestinian Jews in the 2nd Century cultivated Cannabis sativa, as referenced in the (Kil'ayim 2:5) Mishna.
Hemp was used in soups, pies, and tortes by the late Middle Ages in Italy and Germany, but was later primarily used for its fibers, such as the ropes on Christopher Columbus's ships, and even the U.S.S. Constitution (A.K.A. "Old Ironsides").
So: in May of 1607, "hempe" was reportedly being cultivated by the natives at the main Powhatan village, where Richmond, Virginia is now lies. As early as 1619, an Act was passed by the Virginia House of Burgesses that required all Virginia planters to sow English and Indian hemp on their plantations.
In New England, the Puritans are the first known hemp cultivators; circa 1645 CE.
The U.S. became a stand-alone nation in 1776. So the question might read: When did the U.S come to the marijuana?
See the related Wikipedia links listed below for more information:
All the founding fathers cultivated hemp, and probably so did the rest of the country.
Hemp production was replaced by slave owners with cotton plantations.