This is the US chapter of OpenStreetMap, the free, open-source map of the world created by volunteers all over the globe.
<blockquote>We support the OpenStreetMap project in the United States through education, fostering awareness, ensuring broad availability of data, continuous quality improvement, and an active community.</blockquote>
OpenStreetMap gives ordinary citizens the power and the tools to create a high-quality feature-rich map of their country, their states, their communities and their neighborhoods.
Because the map data is free, anyone can use it to create maps for themselves, their businesses, their schools, their local governments or any other purpose they wish.
More than that, OpenStreetMap US is an organization anyone can join to connect with other mappers or institutional data users. Our members range from mapping enthusiasts who want to contribute their knowledge of their local communities to geodata experts who bring technical skills to the creation of the map and professional users who leverage OpenStreetMap data commercially.