In 1589 Brewster returned to Scrooby where he became leader of the Puritan congregation. He led a Puritan migration to Amsterdam in 1608 and made his living publishing religious books and exporting them to England.
In 1620 Brewster, Edward Winslow, William Bradford, John Carver, and other Separatists based in Holland decided to emigrate to America. One hundred and two people boarded the Mayflower and after crossing the Atlantic they decided to settle at a place they called Plymouth in Massachusetts Bay.
The Separatists established their own government and John Carver was elected governor of the colony. The plan was for the pilgrims to live on fish caught from the sea. However, they were not very successful at this, and by the spring of 1621 half of them had died of starvation or disease. Brewster survived and as the only university educated member of the community was seen as head of the church. William Brewster died in Plymouth, Massachusetts, in April, 1644.