Detective #27 arrived on the newsstands on April 18, 1939, launching the career of my favorite comic book character of all time.
Bill Jourdain has been building towards this with a series of posts. He discusses that first year of the Batman, the dark knight before the arrival of Robin, the Joker and the Catwoman. In another terrific post he discusses the changes that came over the Batmobile during the Golden Age of Comic Books.
Update: See also this post by Bill which points to many of his podcasts about Batman over the years. If you are taking a drive in the car or going out for a bike ride or walk, download one or two and listen. Bill makes an entertaining companion, and I have listened to most of these episodes more than once.
For my own part, I am going to use this opportunity to talk a bit about the Silver Age Batman. You can basically divide the Silver Age Batman into five distinct eras:
1. The "Fill in the Legend" era from about 1955-1958. Initially there was no particular reason to think that comic books were anything more than a fad. But as the characters showed signs of durability, DC began to more carefully fill in the back story for their major characters. On the 10th anniversary of Superman's first appearance DC ran more detailed origins for Superman and Batman both, and as the '50s wore on they ran quite a few stories that filled in the legend of Batman. In Detective #226, we learned that Bruce Wayne had learned to be a detective from a private investigator named Harvey Harris. In Detective #244, we learned of the Australian boomerang master who taught him the skills he later used with batarangs. In Detective #265 we found about about Batman's First Case. There were also stories about how Batman subconsciously designed his costume based on an outfit his father had worn to a masquerade ball (Detective #235) and how he learned his disguise tricks from a Hollywood makeup artist (Detective #227).
2. The "Good Grief" era from about 1958-1964. Jack Schiff had long been Batman's de facto editor according to most accounts, but virtually from the start of his official editorship the stories took a dramatic turn towards extremely cheesy science fiction plots. Batman continually found himself up against some horrific monster, or an alien, or turned into some bizarre form himself. The creme de la creme of this era has to be this cover:
3. The New Look. I did an extensive post on this a month or so ago, on the 45th anniversary of the New Look. To brief it up for new readers, the New Look was a modest improvement on the Jack Schiff era and perhaps as best as can be expected given certain contractual realities to Bob Kane.
4. Dadadadadadaduh! Batman! The Batman TV era, with lots of POW! and ZAP! Mostly horrible.
5. The post-Moldoff years. Apparently DC managed to pay off Bob Kane around 1968 and Julius Schwartz was free to contract with new artists. Initially the most significant change was to dump Sheldon Moldoff (who had ghosted about 90% of the Silver Age Batman art for Kane) and retain Irv Novick. While Novick did not become as hailed as his cover artist and eventual successor on the series, Neal Adams, he definitely deserves as much credit as Adams for returning Batman to his "creature of the night" roots. This is the only really good portion of the Silver Age Batman, although there were good elements and individual stories during each of these segments.
Some of my other prior posts on Batman that you might enjoy:
A discussion of Ace, the Bat-Hound.
Robin's romance with Bat-Girl.
One of my older posts on Batman and Guns is now the #1 Google search result for that topic.
Update: See also here for a very funny cartoon take.