first US president to receive huge amounts of mail was FDR

Unlike his many predecessors, FDR used to encourage the American people to write him with their thoughts. At times, the President used to boast to Congress concerning the volume of his mail in favor of his programs, but the mails did not simply deliver stamped envelopes:

“Almost anything you can think of has arrived as a gift at some time or another – dogs, sheep, eagles, baby chicks, toads, alligators. Mr. Roosevelt has never received any lions, but Calvin Coolidge got two, from Johannesburg…”