Oct 1, - In what ways did migrations across North America intensify conflicts? STUDY TIP Use these essential questions to guide your review of this. Study the Period Overview, Summary & Timeline Notes, and AP Exam AP Exam Questions Period 3 Gilder Lehrman APUSH Study Guide: Period 3. College Board Key Concepts Covered: Key Concept Europeans developed a variety of colonization and migration patterns, influenced by different imperial.Having bought a subscription, you can download this or other directories on our website. To download the file, click on the button below.