In the Summer of 1963, Flint, Michigan is home to the Watsons, a close knit family made up of Daniel and Wilona Watson, (Wood Harris and Anika Noni Rose) and their three kids, 15-year-old juvenile delinquent Byron (Harrison Knight), nerdy 11-year-old Kenny (Bryce Clyde Jenkins) and eight-year-old adorable sister Joetta (Skai Jackson). When Byron’s antics go over the top, his parents realize enough is enough and they decide the family needs a dose of Grandma Sands' (LaTanya Richardson Jackson) no nonsense approach in Birmingham, Alabama.
So the Watsons load up their 1948 Plymouth Brown Bomber outfitted with a true tone Ultra-Glide turntable and head South with plenty of comedy en route. When they finally make it to Birmingham, they meet Grandma Sands and her friend, Mr. Robert (David Alan Grier), who show them around town and the Watsons discover that life is very different there than in Flint – and not necessarily for the better. During that historic summer, the Watsons find themselves caught up in something far bigger than Byron’s antics; something that will change their lives and country forever.