The simplices in this dataset correspond to co-sponsorship of bills in the United States Congress, derived from James Fowler's datasets: http://jhfowler.ucsd.edu/cosponsorship.htm Each simplex represents one bill, and the set of vertices is the set consisting of the sponsor and co-sponsors. Timestamps are in days and represent when the bill was introduced. The file congress-bills-names.txt contains the names of the congresspersons.