It all started after the death of Queen Elizabeth I of England. King James was the ruler after the death of Elizabeth I. King James was a Catholic, and the Pilgrims had to flee to a different island for religious freedom.
The Speedwell had been leaking on her voyage from the Netherlands to England, though, so they spent the next week patching her up. On the 5th of August, 1619, the two ships finally set sail for America. But the Speedwell began leaking again, so they pulled into the town of Dartmouth for repairs, arriving there about August 12th.
The Speedwell was patched up again, and the two ships again set sail for America about August 21. After the two ships had sailed about 300 miles out to sea, the Speedwell again began to leak. Frustrated with the enormous amount money and of time lost, and their inability to fix the Speedwell so that it could be sea-worthy, they returned to Plymouth, England, and made the decision to leave the Speedwell behind.
The Mayflower would go to America alone. The cargo on the Speedwell was transferred over to the Mayflower; some of the passengers were so tired and disappointed with all the problems that they quit and went home, while others decide to make the Mayflower even more crowded. Some of the families where separated.
On the 9th of November in 1620, the Mayflower landed on the Cape Cod. Here half of the Pilgrims survived the first winter. The Pilgrims were busy trying to farm but could not farm in the rock hard soil.
Then one day an Indian named Samoset warmly greeted them. A few days later the Indians and the Pilgrims met. An Indian named Squanto, and Samoset decided to help the Pilgrims farm. A few months later, a year after their arrival, the Pilgrims decided to have a feast with the Indians.
The Pilgrims did not know how much food they needed to prepare for the families of the Indians for 3 days. When Massasoit, chief of the Indians, came and saw how much food there was. Within an hour his men came back with about 3 times the amount the Pilgrims had made. This was the first Thanksgiving.
Years passed, the friendship broke, children from playing together, to killing each other, etc. and the peace became war.
About Half or more comes from, mayflowerhistory.com/voyage/, not completely in my own words.