Two-hundred and seven: That's the number of players who have just one solitary cap with the U.S. men's national team. Only once did they play in a senior team game. Some of the 207 you have heard of, like former USMNT coach Bruce Arena (1973 vs. Israel), and some you haven't, like Jimmy Ford (1916 vs. Sweden).
Amazingly, two of these one-cappers got their appearance in a World Cup: Walter Dick, in a 7-1 loss to hosts Italy in 1934, while Adam Wolanin played in the 3-1 loss to Spain at Brazil 1950.