There are a handful of “cluster” immigrant communities throughout the United States that blossomed during the immigration influx of the late 19th and early 20th centuries. Exploring “cluster genealogy”—the process of researching those relatives, friends, and neighbors who lived near an ancestor—can often break down brick walls in the search for individual family lines and help to place our ancestors’ lives in historical context. For those descendants who’ve moved away from such traditional immigrant enclaves, 21st-century technology can be used to rebuild “cluster communities” in the virtual world. This lecture will cover: How to identify chain migrations/cluster communities using key records; ways to share and collaborate with other researchers, and the benefits, pitfalls, and obstacles associate with a shift to “virtual” cluster communities; and how to use tools such as social networking sites, Wikis, etc. build online genealogical communities.