"Zoom In is a free web-based platform that helps students build literacy and historical thinking skills through "deep dives" into primary and secondary sources. Choose from 18 content-rich US history units designed to supplement your regular instruction and help students practice skills required by the new, higher standards: reading documents closely and critically, identifying point of view and purpose, engaging in text-based discussions, and writing explanatory and argumentative essays grounded in evidence."

Here is a description of Contextu via Richard Byrne's Free Technology For Teachers posting: Ken Halla, the blogger behind the US History Teachers Blog, has been working on an excellent new site for students of US History. The new site is called ContextU and its purpose is to help students see the greater context for significant events in history. The first iteration of ContextU is focused on the American Civil War. On ContextU students select from a table of contents an event, piece of legislation, or theme to see it in the context of other events, pieces of legislation, and themes leading to the start of the Civil War. Through timelines, Google Maps, diagrams, flow charts, timelines, and text ContextU provides context for each chosen event, piece of legislation, or theme. Students can jump from event to event or from theme to theme by following the hyperlinks within each diagram.