Congress of Architects and Technicians of Historical Monuments in Venice in 1964. It was at this conference that the enormously influential Venice Charter was created, which established much of preservation philosophy that exists to this day and has become ingrained in the National Park Service's Secretary of the Interior's Standards for preservation. Peterson, along with the entire U.S. delegation rejected the charter, however, due to its European focus and the radical emphasis on preservation instead of restoration. In the 1960s, restoration—defined as the "scraping" of later layers of historic fabric in order to restore the appearance of a building to an arbitrary date—was the status quo and represented the majority of preservation work in the United States. The Venice Charter was a radical shift in preservation philosophy that would not become fully accepted in the United States until the 1980s. Peterson also served on the Committee on Principles and Guidelines for Historic Preservation established by the National Trust which helped influence the future direction of the preservation movement. In the mid-1960s, Peterson was appointed as an adjunct professor to the fledgling historic preservation program at Columbia University where he taught early-American building technology. He worked closely with James Marston Fitch to build this program into the first graduate degree program in historic preservation in the country. Columbia's program became the model which spawned the tens of graduate and undergraduate programs in historic preservation that now exist across the United States. In 1970, Peterson established the European Traveling Summer School for Restorationists that allowed architects to view and participate in restoration projects outside the United States. Peterson was a founding member of the Association for Preservation Technology International (APT), which was created in 1968 in an effort to provide better education for the restoration, documentation, and preservation of historic buildings. He became the organization's first president in 1969. APT was enormously influential as it represented the first scholarly outlet for the activities of historic preservation. Peterson's activities through APT helped move preservation from an antiquarian hobby to a professional endeavor. Throughout his career, Peterson was an avid researcher on the history of American building technology. He is best known for his work on Robert Smith, a colonial-era architect which culminated in the publication of his book Robert Smith (1722-1777): Architect, Builder and Patriot by The Athenaeum of Philadelphia and the Carpenters' Company of Philadelphia in 2000. Other topics that Peterson covered