5 links
BlackDog's Father's Day History
blackdog4kids.com
A look at how and when the observance got started.
History of Father's Day
twilightbridge.com
An account of how the observance came into being and the people who helped make it popular.
Infoplease.com: Father's Day Timeline
infoplease.com
Traces the observance from its start in 1910 to the present day.