Chartered by the United States Congress over fifty years ago, the National Trust for Historic Preservation is a private, nonprofit organization which was formed in order "to encourage public participation in the preservation of sites, buildings, and objects significant in American history." Since that time, the National Trust has worked to preserve a host of structures that have some importance to American culture and history, along with providing stewardship to 21 sites (including the home and studio of Frank Lloyd Wright) under their immediate direction. From the home page, visitors can learn about assistance programs available from the National Trust for preserving local Main Streets or structures, along with learning about the various sites administered by the Trust. Perhaps the most helpful section of the site is the area devoted to articles from the Trust’s monthly publication, Preservation. Here visitors can learn about ongoing preservation issues and read selected issues from the current issue and the online archives.