US First day Covers began in earnest about 1909 and, more than anything, were the brain child of a young Philadelphia collector named Philip Ward. Ward went on to become a major US collector and dealer (in those days of the turn of the last Century, poor liquidity in the stamp market forced many prominent collectors to engage in levels of stamp dealing that would be unusual today) owning a collection and stock that were sold to the Weill Brothers in the early 1960s and which would be worth many millions of dollars today. In his youth, Ward developed a passionate interest in stamps and was one of the earliest collectors to service First day Covers.
There are two main types of First day Covers