The voyage from England to America was in 1620. It was a 3,000 mile ride aboard the Mayflower. The Mayflower was a 17th-century sailing vessel. When they arrived in America after their two month trip it was winter. Being winter, it was difficult to find food. Luckily, the Wampanog or, "eastern people" were there to help them out.
The English colonists or, "Pilgrims" celebrated thanksgiving as part of their religion. Thanksgiving was meant for prayer not feast. The prams and the Wampanogs celebrated the first Thanksgiving in the Autumn of 1621. They celebrated it because they were excited for the first successful harvest.