Short answers, pulled from the story.
Mary Jane Jacob describes public art as works that bring art closer to life by removing barriers between creator and viewer. This genre demands visual and physical accessibility to all people who enter its space.
President Roosevelt launched the New Deal program during the Great Depression to develop national pride. Federal Art Project initiatives altered the relationship between artist and society by making art accessible to all people.
Agnes Denes planted a two-acre field of wheat in downtown Manhattan as part of Wheatfield, A Confrontation in 1982. Joseph Beuys planted 7000 oaks coupled with basalt blocks in Kassel, Germany during the same year.
Richard Serra's minimalist piece Tilted Arc was removed from Foley Square in New York City in 1989 after office workers complained it disrupted their routine. A public court hearing ruled against continued display of the work following those complaints.
The Smithsonian American Art Museum holds over six thousand works in its database currently. Dozens of non-government organizations maintain online public art databases covering numerous areas including National Endowment for Arts and WESTAF.