Question

I'm having a hard time paying attention while reading for history

Answer 1

Some people find it helpful to move around while they read. Speak out loud as well, it will force your mind stay on track. Fidget some, get a fidget idem or just move some part of your bod, this especially helps when you are in school and do not have time for breaks. You can try changing positions every so often. Do not try to work all at once either, read in short burst and take a break to think about what you read. Keep distracting things out of your line of sight. It might also help to change the subject material once and a while.
I hope this is a little bit helpful :)