The idea first came about one night in 2009, after leaving a wad of clay on a PlayStation controller while the game Oddworld: Abe's Exoddus was playing, causing Abe to run into a wall repeatedly. Later on that night, the two creators came up with the character of Sarmon, who is actually the first character ever created for the Abe series, even before Abe, and he eventually evolved into Alex Mania.
Abe was the second, yet more developed, character created for the series, hence the namesake. Abe's character was developed from mid-2009 to mid-2011, when the first Abe video, Abraham Trilogy - Part 1: Abe Gets a Blowjob was released. Although this was the first video released on Abe's channel, it was not the first Abe video ever planned/created. Abraham Short - Abe's Strip Club Adventure was actually started before Abraham Trilogy - Part 1, and even earlier than that was a story called "Abe.txt", dated May 9, 2011:
"Abe was a happy individual in his elder years. He enjoyed the simple things in life, such as crouching down and dropping a steaming hot fudge pie on the top of a city bus. One day, Abe decided to journey to Asia on his tricycle. He couldn't ride over the ocean, disappointing him greatly. He pulled off his shirt. He then put it back on. He jumped into the ocean and swam to Home Depot. He marvelled at all the things Home Depot had to offer. He purchased an empty red toolbox. He then sprinted home."
For a while, Abe stories were an exclusive thing, as the two creators made them up impromptu by themselves, or at parties. In May of 2011, development began on an Abe video to be uploaded on one of the creator's channels, but it was instead decided that Abe would have his own YouTube channel altogether, although it wasn't expected that it would turn into a series with an actual story.
In early 2012, an extras channel was created in the same naming scheme as Abe's channel, but instead with Alex Mania's name, that had anything from musical compositions made specifically for Abe to Fandubs to unfinished, previously unreleased Abe videos.
In May of 2012, in preparation for the anniversary of Abe videos, a finale was released for Season 1 on May 17, 2012.
On May 31, 2012, the 1 year anniversary of Abe Trilogy - Part 1, The Abraham Trilogy - Part 2: Abe Paints the Town Red was released, though it seemed heavily unfinished.
Season 2 remained in development until Abraham Short - Abraham Short, where it was discontinued and the series no longer ran in seasons. May of 2013 broke the 1 year tradition of releasing a new Trilogy each year, as there was a series finale being planned instead, to be released whenever the full Abe world story is complete.
As time has gone on, the interval between released Abe videos has become longer and longer, as more thought has gone into the videos after the end of Phase 1. Between Abraham Short - Megalo and Abe Go To the Zoo and Abraham Short - Abe Gets It Together, the style was drastically changed and transitioned from Phase 2 to Phase 3.