Rootlines began in 2012 as a private database for the genealogical research of the founder, Virginia N. Mitchell (M.A.), who had been working as a professional genealogist for over ten years. During the first six months, it gained the support of several friends and family members, who became the organization's first volunteers.

In 2014, it served as a project for Virginia's master's degree in Public History and received top marks for content, organization, and effort, as well as the inclusion of volunteers, making it a true public history project for involving the public via documents and data entry. It also served as a testament to Virginia's management skills and creativity in managing online volunteers, as well as her professionalism in genealogical and historical research. As the volunteer base grew, so did Rootlines.

In January of 2015, the decision was made to proceed with the idea of making Rootlines a genealogical organization that would benefit the public by providing access to documentation at an affordable cost. The project database is currently free to the public and is supported by grants and donations from the community, as well as friends and family members. Today, Rootlines hopes to serve the public by continuing to provide accurate genealogical information and documentation to the public.