In November, 2014 the National Heritage Museum in Lexington, Mass., offered a presentation titled "How to Do History with Online Mapping Tools" as part of a series related to the Museum and Library’s collection of historic maps sponsored by the Ruby W. and LaVon P. Linn Foundation. The invited presenters were Jessie Partridge from the MetroBoston DataCommon, a provider of free applications that make it possible to map data, and Joanne Riley, University Archivist and Curator of Special Collections in the Healey Library at UMass Boston. Both presenters helped lay historians, data fans, and map enthusiasts discover how visualizations of data and space related to our region can help us understand our history. Riley's presentation and handout are made freely available here.