First Day Cover collecting in the United States began gradually. Until about 1920, no one made FDCs and the ones that we have were serendipitously prepared by ordinary postal users going to the post office and accidentally using a new issue on the day that it came out. Gimbel Brothers, the department store in Philadelphia, mailed their May 1901 monthly statements to customers with the newly issued 2c Pan American (#295) and for years you could find #295 FDCs with Gimbel corner cards (current catalog values $2500) in dealer 5c boxes in the Philadelphia area (I did). Beginning about 1920 Phillip Ward and Edward Worden began collecting, preparing and promoting First Day Covers and their activity extended interest back to older issues. Researchers established issue dates and where no FDCs were know, collectors began to collect EKUs (earliest known use). By 1960, a FDC collection was part of most serious US collections and most of the Baby Boomers grew up with FDCs.
But collecting FDCs has fallen out of favor and continues to do so. This is for several reasons. First, cachets and FDC preparation has gotten expensive and cumbersome and collectors can no longer service their own. Second, FDCs and their albums take up alot of space and when collectors run out of room on their shelves what goes first are the peripheral areas. Third, FDCs have performed very poorly as an investment. A current issue FDC costs $2 or more and resells at 5c, a beating most collectors would rather not take. Fourth, the Readers Digest and other non philatelic companies promoting FDCs have given them a bad name. And last, the incredible quantity of mint new issues that the United States issues annually can well fill the amount of time and money that the average collector wishes to spend on his hobby and there is no longer any need that FDCs fulfill. In 1953, the USPS issued three stamps so that collectors had plenty of time and money for FDCs and plate blocks. Now there are over 100 issues annually. Most people spend only an hour or two per week on their hobby so today’s US collectors have plenty to do with just what the USPS sends to their doors.