Johnny Tremain Genre
Young Adult Literature; Coming-Of-Age; Historical Fiction
Let's get the obvious one out of the way first. Johnny Tremain, published in 1943 but set in 1773-1775, is a work of historical fiction, meaning that it's set in the real world but either prior to the author's birth or outside living memory. People disagree on the exact requirements for historical fiction, but Johnny Tremain fits both criteria, so it definitely falls into this category.
Now, young adult literature and coming-of-age novels have a lot of overlap because most novels about adolescents deal in some way with how those adolescents grow up. Growing up is, arguably, the main task of adolescence. But we know that Johnny Tremain is a young adult novel because of the age of the protagonist (14-16) and because Johnny is seeking to answer the primary question with which many young adult novels deal: who am I? The fact that he eventually figures that out, which allows him to grow up, means this is also a coming-of-age novel.