The WB's announcement that it was canceling the show came at a time when it was rated second only to Smallville (2001) among 18-to-34-year-olds. Earlier in the same month, WB's weekly ratings release revealed that "Angel" had earned "outstanding year-to-year gains" among demographic groups.
Christian Kane (Lindsey) originally auditioned for the role of Riley Finn on Buffy the Vampire Slayer (1997). Show creator Joss Whedon liked Kane so much that he asked him to play the character of Lindsey instead.
In the opening credit sequence of every episode, there is an image of a woman standing by the side of a street. This is not actually taken from any episode of "Angel," but rather it's from the "Buffy" episode Anne (1998), though the scene takes place in the show's setting of Los Angeles.
Liam/Angel was born in 1727, and turned into a vampire in 1753, as established in The Prodigal (2000), and he counts 1753 as his birth year. Although he spent one hundred years in a hell dimension due to Buffy's actions in Becoming: Part 2 (1998), he does not count those years as part of his lifespan, and told Cordelia in Dear Boy (2000) that he was 247. Allowing for aging, he is 251 years old at the series end.
The character Doyle wasn't originally supposed to be an Irishman, but was written as such when Glenn Quinn was cast. The role of Doyle was Quinn's first role where he was able to use his own Irish accent.