The 1970 Census was the first United States decennial census to be released in machine-readable format, allowing cartographers sudden access to large amounts of aggregated demographic data about the entire United States. This blog post explores early computer cartography mapping techniques that took advantage of the new census format, including SYMAP and SYMVU, as demonstrated in an atlas held by the Geography & Map Division titled “The Puget Sound Region: A Portfolio of Thematic Computer Maps.”