David’s comment: My father-in-law went to RPI, an engineering collge in update NY founded by Rennselaer’s family. That’s what the “R” stand for.
Representative | Federalist | 
VAN RENSSELAER, KILLIAN KILLIAN, (cousin of Jeremiah Van Rensselaer, uncle of Solomon Van Vechten Van Rensselaer), A Representative from New York; born in Greenbush, Rensselaer County, N.Y., June 9, 1763; completed preparatory studies and attended Yale College; studied law; was admitted to the bar in 1784 and commenced practice in Claverack, N.Y.; private secretary to Gen. Philip Schuyler; elected as a Federalist to the Seventh and to the four succeeding Congresses (March 4, 1801-March 3, 1811); resumed the practice of law; died in Albany, N.Y., on June 18, 1845; interment in a private cemetery at Greenbush, N.Y.- Killian Van Rensselaer on Wikipedia