Though FDR refused to sit at a table with thirteen guests, President Woodrow Wilson believed that 13 was his lucky number. Indeed, on one occasion, Wilson ordered a ship to slow down -- so that he could arrive in Europe on the 13th of the month.

[The back of the U.S. $1 bill displays a pyramid with thirteen steps. The motto above it, annuit coeptis, contains thirteen letters -- as does that (e pluribus unum) written on the ribbon in the eagle's beak. There are thirteen stars above the eagle's head, thirteen stripes on the shield, thirteen war arrows in its left talon, and thirteen leaves on the olive branch in its right talon. The reason? Originally, there were thirteen states.]