Green Arrow and Speedy both debuted in More Fun Comics #73 (November 1941). Created by writer and DC editor, Mort Weisinger, and artist, George Papp, they two character were very much answers to the companies star duo, Batman & Robin. Aside from Batman & Robin, the duo also was an answer to Robin Hood.
The teaming of Green Arrow and Speedy debuted in the pages of More Fun Comics. Green Arrow was Oliver Queen who was originally a wealthy playboy who was also a museum curator and archeologist specializing in Native Americans. Sadly his museum was burnt down by a couple of criminals so he travels the Lost Mesa to restart his museum. That is where he met Roy.
Roy Harper was the survivor of a plane crash that killed his parents. The only other to survive was Quoag, the Native American servant to the Harper's. Quoag taught Roy skills such as archery to aid in survival is Lost Mesa.
When Ollie arrives it is discovered that criminals have been following him which ended in the death of Quoag. Roy Harper was taken in my Ollie and together the two decided to become masked men. With a Robin Hood theme of appearance, the two took on the streets of Star City with bows and arrows. They gained their superheroes names, Green Arrow and Speedy, from criminal remarks.
The feature was somewhat of a success and took the previous cover feature of More Fun Comics, Doctor Fate, place and headlined the book in early 1942. The teaming of Green Arrow and Speedy was nothing less than a Batman and Robin rip off. Aside from being a playboy and his ward the duo had the Arrowcar (ala the Batmobile), the Arrowcave, and a clown arch foe, Bulls Eye (ala the Joker).
In addition to their star status in More Fun Comics the duo also helped lead in another team in Leading Comics. This team was the Seven Soldiers of Victory which starred the like of DC owned heroes the Star Spangled Kid, Stripesy, Vigilante, Shining Knight, and the Crimson Avenger. They stuck with the team from their debut in the winter of 1941 until the spring of 1945 when Leading Comics became a humor comic.
Green Arrow and Speedy stayed on the cover until 1945 when Superboy was added as a feature and the book until the year 1946. Around this time superheroes have started to become less popular in the marketplace leading to the creation of many new genres such as crime and romance. More Fun became a humor comic, like it originally was in the first place, to accommodate new tastes in comic reading.
Green Arrow and Speedy both survived moving over with fellow More Fun stars Superboy, Mort Weisinger creation, Aquaman, Adventure Comics. The duo of Green Arrow and Speedy would no longer get to headline as the more profitable star, Superboy (The Adventures of Superman When He Was a Kid!), had cover place. However Green Arrow and Speedy did survive throughout the rest of the 40's and into the 50's being one of the few superheroes to actually do so.
Unlike other DC heroes the duo of Green Arrow and Speedy lasted throughout the 50's by hiding the back features of Adventure Comics. With the introduction of the Silver Age Flash, Barry Allen, the DC universe saw many reinventions. Green Arrow and Speedy were one of the left over characters to get reinvented.
Jack Kirby, known for such creations as the DC Fourth World and the Marvel universe, and writer, Ed Herron, reinvented the duo with reinventions that have pretty much been left unchanged for the majority of years to come in 1958's Adventure Comics #250. These reinventions led to Green Arrow working alone well before he took Speedy under his wing and led to a quitting of his day job. No longer was a museum curator as Oliver Queen though simply just a wealthy playboy with Queen Industries.
After falling overboard his yacht he was left on an island where he learns archery and creates clothing with a resemblance of Robin Hood. He later got off as the island when he spotted a ship. He soon realized this ship was being taken over by mutineers and after the defeat of these foes he decides to become the superhero known as Green Arrow.
Roy's origins with his dead parents barely changed aside from the fact that the Native American was no longer Quoag though Chief Thunderhead. Thunderhead encourages Roy to forge his own destiny which led to Roy becoming a hero and meeting with Green Arrow dubbing him "Speedy". Later retellings would have Roy be taken in by the Navajo, Brave Bow, when Roy's forest ranger dad died in a forest fire.
The duo continued to fight crime with each other in Adventure Comics and World's Finest Comics. In 1960, Green Arrow and Speedy were booted from their place in Adventure Comics due to page reduction. In 1964, they were booted out of World's Finest for similar reasons. For the rest of the Silver Age; Green Arrow and Speedy went their own ways as it seems as Green Arrow found his way as Justice League member in Justice League of America #4 (May 1961) where Speedy became an official member of the Teen Titans in Teen Titans #19 (February 1969) after tagging along with them on many adventures.
Now without an actual feature, Green Arrow and Speedy teamed up more with characters of their age in the Justice League and Teen Titans titles writers started to experiment more with Green Arrow in particular.
Since their debut, Green Arrow and Speedy has been nothing more than an archer themed Batman and Robin. Now that they were both separated and Green Arrow's recurring role in the Justice League since its beginnings writers started to experiment more and more with Green Arrow trying to lead him away from the Batman mold he was created in.
This led to artist, Neal Adams, redesigning Green Arrow with a Van Dyke style goatee and writer, Denny O'Neil, taking away his fortune making his concerns less about the League and more about the crime on the streets once more. In addition to this move he starts co-starring in the floundering book, Green Lantern, where Green Arrow started a friendship with Green Lantern Hal Jordan and starts a relationship with the Earth jumping hero, Black Canary. To further himself even from the Batman mold was the lost of Speedy when in the iconic comic, Green Lantern #85 (August 1971), Green Arrow and Green Lantern catches Speedy doing heroin.
This event pretty much ended the team of Green Arrow and Speedy. Both heroes going their own ways only working with each other on occasions.
The Modern Age
The events of the DC's 1985 clean up event, Crisis on Infinite Earths, led to no new revival in the teaming of Green Arrow and Speedy. In 1988 artist and writer, Mike Grell, took Green Arrow even further away from his roots meaning even further away from a Speedy. After Green Arrow #80, Mike Grell left and twenty issues later Oliver was killed only to replaced by his long lost son, Connor Hawke.
Meanwhile Speedy enjoyed some shots in the critically acclaimed New Teen Titans series where he gained a job as a government agent free of drugs and even speaking against them. He also gained a daughter, Lian Harper, from the assassin, Cheshire. In addition to all of this he left his Speedy identity behind and Roy Harper took on the name of Arsenal just like his other ex-sidekicks Robin, Dick Grayson (who took on the name of Nightwing), and Kid Flash, Wally West (how took on the Flash identity after Barry Allen, the Silver Age Flash, died in the Crisis).
All of this leading to what seemed to be the end of the Green Arrow and Speedy team for good. It wasn't until Kevin Smith's 2001 story, Quiver, that a new Speedy rose up when Oliver was back in the land of the living as Green Arrow and met young teen prostitute, Mia Dearden. Taking her in from her life of shame and giving her a home she soon began training to become the next Speedy. In 2005's Green Arrow #45, she takes on the identity and the team of Green Arrow and Speedy is once more. Though not seen together all the time like the original team of Green Arrow and Speedy they did work together. Mia even joined the rank of the Teen Titans.
As for Roy, he continued operating as Arsenal and worked with such as the Outsiders and the Titans. He later joined the ranks of the Justice League in 2006's Justice League of America #1 taking the name Red Arrow. Roy and Oliver did make amends though both were on there own from each other.
The Green Arrow and Speedy team of Mia and Oliver lasted until 2011 when DC Comics decided upon a line wide reboot known now the New 52.
In DC Comics universe wide reboot, the New 52, the sidekick/mentor relationship between Green Arrow and a Speedy was absent. There were however references to an old partnership between Green Arrow and Arsenal, aka Roy Harper, the original Speedy. Roy was taken in by Green Arrow where he worked as a sidekick fixing and building crime fighting tools for the Emerald Archer. There was a fall out between the two and had little relationship throughout the stories of the New 52.