U. S. History Study App - Lessons, Quizzes, Glossaries, Flashcards. Features: Study progress. Quiz progress. 32 Study units. 168 Lessons. 32 Quizzes. 280 Practice questions. 109 Glossaries. To develop U. S. History, we solicited ideas from historians at all levels of higher education, from community colleges to Ph. D. Granting universities.