Top of my list is Never Caught, the Story of Ona Judge: George and Martha Washington's Courageous Slave Who Dared to Run Away Young Readers Edition by Erica Dunbar and Kathleen Van Cleve. It wasn't around, alas, when I was a child but I gifted it a number of teacher friends last holiday season and all reported back it hits the sweet spot around text complexity and personal interest.

Nikki Grimes’ One Last Word: Wisdom From the Harlem Renaissance is a great introduction to the period and the book is gorgeous.

Betty Before X is written by Ilyasah Shabazz, Shabazz and Malcolm X's daughter, and it gets at the role women play in movements led by men and can open a whole bunch of conversations about whose names get remembered.

Finally, I Am Not a Number deals with consequence of historical decisions on people living today. The author, Jenny Kay Dupuis, is Canadian and First Nations so it's not American-centric but the story speaks to events that happened below the border as well (just without the modern day truth and reconciliation work.)

The Magic Tree House series by Mary Pope Osborne and the I Survived series. Also, The Birchbark House, Island of the Blue Dolphins, Sadako and the Thousand Paper Cranes, Kira-Kira, Pharaoh's Daughter by Julius Lester, Fever 1793 by Laurie Halse Anderson, Silent Thunder by Andrea Davis Pinkney, Esperanza Rising by Pam Muñoz Ryan, and Bless Me Ultima.

I also read Diary of Anne Frank around that age, but I know some people feel it's inappropriate for younger children.

I read quite a few books from the "Childhood of Famous Americans" series that my mother had as a child in the 40s-50s. I was especially interested in the figures like Dolly Madison and Abigail Adams. I liked that they were real people, but started with childhood, so I could relate to them.