While it’s very easy to make parallels between Thanksgiving and Sukkot, the origins of Shavuot also make the spring holiday of the Torah a harvest holiday: this can be kept in mind during the celebrations of Thanksgiving.
Sukkot falls in the autumn, and celebrates the gathering of crops. Some historians have claimed that the Puritans based the Thanksgiving celebrations on the Sukkot celebrations of the Torah. However, the second harvest festival, Shavuot, should not be ignored. Shavuot’s original name was Hag HaKatzir. It was the beginning of the harvest season and can in fact be translated as the harvest holiday. Another name for Shavuot is Hag HaBikurim—the holiday of the first fruits - for the sacrifices of fruits which were offered at the temple.