this link will show you exams from January 2010 to August 2015. If you dig deeper you'll find exams that go back to January 1998. (And for fun (?), you can click here for translated editions of the exam in Chinese, Haitian Creole, Korean, Russian, and Spanish. Here's the same test as above, but in Russian:)
But wait, there's even more. Here's a link to a 2009 released version of a sample California 11th-grade U.S. History--Social Science exam. And here's a link to released versions of Texas's end-of-course U.S. History exams for 2014 and 2015.
Bottom line: There is an inexhaustible supply of free test questions for use all through the year, be it for unit, chapter, or end-of-year-review exams and quizzes.
Caveat: These are pdf versions of paper-pencil tests, so they are not interactive. You will just have to print them out to share with your students.