Pilgrim Fathers (or simply Pilgrims). These Separatists or English Dissenters were religious refugees who had fled England to Amsterdam in 1608 and moved to Leiden the next year. They lived and worked in that city for about 12 to 20 years. In 1620, their emigration began. They left Leiden by canal, going to Delfshaven where they embarked on the "Speedwell," which took them to Southampton. But the "Speedwell" proved leaky and had to be sold, so they transferred to the Mayflower. The "Mayflower" undertook the famous voyage to New England in 1620 alone. In the 19th century the colonists' first harvest festival after their arrival at Plymouth Colony was identified as the origin of the annual Thanksgiving celebration in the United States.