Walaikum-asalam,

I can speak to the US History portion of the syllabus. I would advise using Majumdar's book as a deep dive into US History material and then following up with another source to review and corroborate the material. There are a lot of sources online that are accurate (anything prepared for US High School Students for their AP US History Exams).

Spend the rest of your time practicing essay responses (and MCQs) to past US history examinations. These can also be found online.

Good luck.

Best,
Qasim