Question: In which year was the University established at which Justin Hansford, for academic year 2016-2017, was a visiting professor of law ? 
Sentence (from "Georgetown Law"): Georgetown University Law Center (commonly referred to as Georgetown Law School or Georgetown Law) is one of the professional graduate schools of Georgetown University, a private research university located in Washington, D.C. Established in 1870, it is the second largest law school in the United States, and receives more full-time applications than any other law school in the country.
Relevant evidence: Yes