GREAT EPOCHS IN AMERICAN HISTORY

I have tis set of books vols. 1-4 and 6-10 whe i got them 5 was not with them. they are hard back but covers aren't in very good shape and there are no middle bindings on the but the insides are in good condition.they are calle great epochs in american history. i have no idea why i bought them which was more than 10 years ago, or what i paid. if any one cam tell me about them and if they are worth any thing i would apreciate it