Yes, Thanksgiving is a federal holiday, and it is celebrated on the fourth Thursday of November every year. For this year, Thanksgiving will be celebrated on the 28th of November, 2019. Thanksgiving celebration does not have a fixed date, and that's why the date for this year will be totally different from that of next year. However, the constant thing is that it is celebrated on the fourth Thursday of November every year.
Thanksgiving has been a federal holiday since 1941, although it actually didn't start as a federal holiday because the story behind Thanksgiving celebration is a religious one. Thanksgiving is an important event in the United States because it is also one of the ten federal holidays in the United States. That's why you will not see people going to work on Thanksgiving Day, and they will still get paid for that day, although, in the private sector, some employees celebrate this holiday at their various places of work.