"The Factbook is a comprehensive resource of facts and statistics on more than 250 countries and other entities." A good source for demographic, political, and economic information from the Central Intelligence Agency.
Oral histories, letters, diaries, and other personal narratives from more than 2,100 people providing a "unique and personal view of what it meant to immigrate to America and Canada between 1800 and 1950." Search by nationality, year of immigration, point of entry, etc. (Alexander Street Press)