Question: Who created "Glad Day"?
About the article "Vitruvian Man", section "Derivative works".

Candidate passages:
""When you look for the bad in mankind expecting to find it, you surely will find it.""
Although a quote similar to this was attributed to Abraham Lincoln and inserted by the director into the 1960 Disney movie version of the story, it is actually, as written here, from the original book and not attributed.
The novel's success brought the "Pollyanna principle" (along with the adjective "Pollyannaish" and the noun "Pollyannaism") into the language to describe someone who seems always to be able to find something to be "glad" about no matter what circumstances arise.
It is sometimes used pejoratively, referring to someone whose optimism is excessive to the point of naïveté or refusing to accept the facts of an unfortunate situation.
This pejorative use can be heard in the introduction of the 1930 George and Ira Gershwin song But Not For Me: "I never want to hear from any cheerful pollyannas/who tell me fate supplies a mate/that's all bananas.
"The word "pollyanna" may also denote a holiday gift exchange more typically known as Secret Santa.
This term is used in Philadelphia and the surrounding areas of Pennsylvania.
It can instead mean a gift exchange rotation in which several families each give gifts to one other family in the "pollyanna" each year.
This is often done when siblings in a large family begin to have children of their own.
"Pollyanna" is still available in reprint editions.
At the height of her popularity, Pollyanna was known as "The Glad Girl", and Parker Brothers even created "The Glad Game", a board game.
"The Glad Game", a type of Parcheesi, was made and sold from 1915 to 1967 in various versions, including: "Pollyanna - The Glad Game"; "Pollyanna - The Great Home Game"; "Pollyanna - Dixie"; and "Pollyanna".
The board game was later licensed by Milton Bradley but has been discontinued for many years.
A Broadway adaption was mounted in 1916 titled "Pollyanna Whittier, The Glad Girl", starring Helen Hayes.
"Glad Clubs" appear to have been popular for a while; however, it is questionable if they were ever more than a publicity gimmick.
Glad Clubs may have been simply a means to popularize "The Glad Game" as a method for coping with the vicissitudes of life such as loss, disappointment, and distress.
Nevertheless, at least one "glad club" existed till at least 2008, in Denver, Colorado.
In 2002 the citizens of Littleton, New Hampshire unveiled a bronze statue in honour of Eleanor H. Porter, creator of the Pollyanna books and one of the town's most famous residents.
The statue depicts a smiling Pollyanna, arms flung wide in greeting.
Littleton also hosts a festival known as "The Official Pollyanna Glad Day" every summer.
The vocalized version of the song "Pollyanna" for the video game Mother characterizes a cheerful girl that believes in fairy tales and optimism, but disregards any comments towards her sanity.
The girl rejects the negative opposition against her and the mockery that comes with it, saying "You can call me 'Pollyanna'/Say I'm crazy as a loon".
The name of the song, and that of the girl in the song, is most likely a direct characterization of Porter's character.
Another theory is that the name is based on Ana, a character in the game.
The celebrated American science fiction writer Ray Bradbury described himself as "Janus, the two-faced god who is half Pollyanna and half Cassandra, warning of the future and perhaps living too much in the past—a combination of both". 
 John Glad (born December 31, 1941), an American academic, retired professor of Russian studies Glad (duke), ruler in the territory of Banat, who was defeated by the Magyars during the 10th century  
 "Anatomy of a coup", Glad Day Press, 1970      
Glad Valley is an unincorporated community in Ziebach County, South Dakota, United States.
Glad Valley is located on South Dakota Highway 20 west of Isabel.
Glad Valley was established in 1926 by G. J. Unterseher, who opened a store there near the Gold Valley farm. 
The music video for "I'm Glad" was directed by David LaChapelle and it pays homage to Adrian Lyne's 1983 film "Flashdance", with the same story of an aspiring young dancer who welds by day and gyrates by night in a friendly neighborhood girlie bar, showing Lopez in a series of vignettes lifted from the movie, even borrowing its characteristically 80’s mote-softened lighting.