To understand Tweed one must know Wood. For Tweed studied Wood, analyzing minutely every move he made. Until January 1, 1855, when Wood was inaugurated Mayor in New York's City Hall, an edifice justly appraised by F. Hopkinson Smith as one of the three most exquisite gems of architecture in the United States, Tweed's study heretofore was, perforce, restricted. But thenceforward, all of Wood's actions were matters of public record or known to the politicians who surrounded him. And no one had more of the inside gossip than Tweed, who spent such time as he could away from his business, haunting the corridors of the City Hall, or Delmonico's, or some other haunt of the bon ton of the day, swapping what he had gathered with other foes of Wood who foregathered in the evenings in the Wigwam, then a stately Colonial pile facing the eastern side of City Hall Park.