Original continuity

The Tom Swift Sr. and Jr. Continuity is the first Tom Swift continuity. Starting with the events of the first book in the Tom Swift Sr. Adventures (Tom Swift and His Motorcycle (1910)) and continuing through the final volume of The New Tom Swift Jr. Adventures (Tom Swift and the Galaxy Ghosts (1971)), the stories in this continuity chronicle the adventures of Tom Swift, and later his son, Tom Swift Jr. While the majority of the Tom Swift Sr. stories are more about going on adventures and "tweaking" devices that already exist (such as motor boat engines), and paving the way for Swift Enterprises to exist than inventing new devices, the Tom Swift Jr. Adventures are full of stories where the adventure would not be possible unless Tom Swift Jr. had not invented the usually titular invention. Plus, while most of the "tweaks" and inventions that were introduced in the Tom Swift Sr. series have come to be available in the real world, the majority of the Tom Swift Jr. inventions are based on theories for "new" technologies that were being speculated on in the 1950's and 1960's, but have not been invented or have proved to be, realistically, implausible.

In Tom Swift IV, a couple of books contained references, that were not usually correct, to events that had occurred in the Tom Swift Sr. series. The most notable book being Monster Machine that tried to have the Tom Swift Jr. of that continuity come across a tunnel in South America that his grandfather had worked on (Tom Swift and His Big Tunnel), even though the location of the tunnel in Monster Machine does not correspond to the location of the tunnel in Tom Swift and His Big Tunnel.

Tom Swift Young Inventor took a mixture of inventions and characters from the Tom Swift Sr. and Jr. continuity and tried to have many of those inventions be invented by the Tom Swift Sr. of this new continuity, even though in the Original Continuity the inventions mentioned had been made by both father and son.

Tom Swift Sr. Adventures
The first novels to feature the Tom Swift character were released in 1910 by Grosset & Dunlap. The series was created by Edward Stratemeyer, and written by several ghostwriters in its duration.

The first 38 titles were published by Grosset & Dunlap, with two ghostwriters: Howard Garis wrote the first thirty-five titles, while Harriet Adams wrote the final three. Two more titles were published as a part of the Big Little Book series (by rival Western Publishing), and were ghostwritten by Thomas Moyston Mitchell.