In this lesson you will learn how to create vector layers based on scanned historical maps. In Intro to Google Maps and Google Earth you used vector layers and created attributes in Google Earth. We will be doing the same thing in this lesson, albeit at a more advanced level, using QGIS software.

In this lesson, you will learn how to georeference historical maps so that they may be added to a GIS as a raster layer. Georeferencing is required for anyone who wants to accurately digitize data found on a paper map, and since historians work mostly in the realm of paper, georeferencing is one of our most commonly used tools. The technique uses a series of control points to give a two-dimensional object like a paper map the real world coordinates it needs to align with the three-dimensional features of the earth in GIS software (in Intro to Google Maps and Google Earth we saw an ‘overlay’ which is a Google Earth shortcut version of georeferencing).

In this lesson you will install QGIS software, download geospatial files like shapefiles and GeoTIFFs, and create a map out of a number of vector and raster layers. Quantum or QGIS is an open source alternative to the industry leader, ArcGIS from ESRI. QGIS is multiplatform, which means it runs on Windows, Macs, and Linux and it has many of the functions most commonly used by historians. ArcGIS is prohibitively expensive and only runs on Windows (though software can be purchased to allow it to run on Mac). However, many universities have site licenses, meaning students and employees have access to free copies of the software (try contacting your map librarian, computer services, or the geography department). QGIS is ideal for those without access to a free copy of Arc and it is also a good option for learning basic GIS skills and deciding if you want to install a copy of ArcGIS on your machine. Moreover, any work you do in QGIS can be exported to ArcGIS at a later date if you decide to upgrade. The authors tend to use both and are happy to run QGIS on Mac and Linux computers for basic tasks, but still return to ArcGIS for more advanced work. In many cases it is not lack of functions, but stability issues that bring us back to ArcGIS. For those who are learning Python with the Programming Historian, you will be glad to know that both QGIS and ArcGIS use Python as their main scripting language.

Google Maps and Google Earth provide an easy way to start creating digital maps. With a Google Account you can create and edit personal maps by clicking on My Places. In the new Google Maps interface, click on the gear menu [icon] at the upper right of the menu bar, and select My Places. The new (as of summer 2013) interface provides a new way of creating custom maps: Google Maps Engine Lite allows users to import and add data onto the map to visualize trends.

Students consult primary and secondary sources to identify the events leading to Abraham Lincoln's assassination and consider whether his assassination was avoidable.

Who Built America? includes a free online textbook, primary document repository, and teaching resource created by the American Social History Project/Center for Media and Learning at the Graduate Center of the City University of New York. The textbook and supplemental resources survey the nation’s past from an important but often neglected perspective—the transformations wrought by the changing nature and forms of work, and the role that working people played in the making of modern America.

Who Built America? offers a thirty-chapter textbook accompanied by drawings, paintings, prints, cartoons, photographs, objects, and other visual media, including links to ASHP/CML’s ten documentary videos and teacher guides that supplement the book’s themes and narrative and offer perspectives on the past that were often not articulated in the written record. Each chapter includes first-person “Voices” from the past—excerpts from letters, diaries, autobiographies, poems, songs, journalism, fiction, official testimony, oral histories, and other historical documents—along with a timeline and suggestions for further reading.

This online edition features supplemental materials designed to help readers understand the practice of history. The more than forty A Closer Look essays, offer readers an in-depth investigation of a significant historical event, cultural phenomenon, or trend that is otherwise only touched upon in a chapter. The seven Historians Disagree essays provide readers with historiographic perspectives on how scholars’ approaches to key topics have changed over time, illuminating how history is an ever-evolving field of study.

The OER also includes the History Matters Repository, featuring more than 2,000 primary source resources from the History Matters: The U.S. Survey Course on the Web site. The items in this fully searchable repository contain contextual headnotes and links to related documents.