Lyman Frank Baum (May 15, 1856 - May 6, 1919), better known as L. Frank Baum, was an American author chiefly famous for his children's books, particularly The Wonderful Wizard of Oz and its sequels. He wrote a total of 14 novels in the Oz series, plus 41 other novels, 83 short stories, over 200 poems, and at least 42 scripts. He made numerous attempts to bring his works to the stage and the nascent medium of film; the 1939 adaptation of the first Oz book would become a landmark of 20th century cinema. His works anticipated such century-later commonplaces as television, augmented reality, laptop computers (The Master Key), wireless telephones (Tik-Tok of Oz), women in high-risk and action-heavy occupations (Mary Louise in the Country), police corruption and false evidence (Phoebe Daring), and the ubiquity of advertising on clothing (Aunt Jane's Nieces at Work).

Baum was born in Chittenango, New York in 1856 into a devout Methodist family. He had German, Scots-Irish, and English ancestry, and was the seventh of nine children of Cynthia Ann (nee Stanton) and Benjamin Ward Baum, only five of whom survived into adulthood. "Lyman" was the name of his father's brother, but he always disliked it and preferred his middle name "Frank".  His father succeeded in many businesses, including barrel-making, oil drilling in Pennsylvania, and real estate. Baum grew up on his parents' expansive estate called Rose Lawn, which he fondly recalled as a sort of paradise. Rose Lawn was located in Mattydale, New York. Frank was a sickly, dreamy child, tutored at home with his siblings. From the age of 12, he spent two miserable years at Peekskill Military Academy but, after being severely disciplined for daydreaming, he had a possibly psychogenic heart attack and was allowed to return home.  Baum started writing early in life, possibly prompted by his father buying him a cheap printing press. He had always been close to his younger brother Henry (Harry) Clay Baum, who helped in the production of The Rose Lawn Home Journal. The brothers published several issues of the journal, including advertisements from local businesses, which they would give to family and friends for free. By the age of 17, Baum established a second amateur journal called The Stamp Collector, printed an 11-page pamphlet called Baum's Complete Stamp Dealers' Directory, and started a stamp dealership with friends.  At 20, Baum took on the national craze of breeding fancy poultry. He specialized in raising the Hamburg. In March 1880, he established a monthly trade journal, The Poultry Record, and in 1886, when Baum was 30 years old, his first book was published: The Book of the Hamburgs: A Brief Treatise upon the Mating, Rearing, and Management of the Different Varieties of Hamburgs.  Baum had a flair for being the spotlight of fun in the household, including during times of financial difficulties. His selling of fireworks made the Fourth of July memorable. His skyrockets, Roman candles, and fireworks filled the sky, while many people around the neighborhood would gather in front of the house to watch the displays. Christmas was even more festive. Baum dressed as Santa Claus for the family. His father would place the Christmas tree behind a curtain in the front parlor so that Baum could talk to everyone while he decorated the tree without people managing to see him. He maintained this tradition all his life.  Baum embarked on his lifetime infatuation--and wavering financial success--with the theater. A local theatrical company duped him into replenishing their stock of costumes on the promise of leading roles coming his way. Disillusioned, Baum left the theater -- temporarily -- and went to work as a clerk in his brother-in-law's dry goods company in Syracuse. This experience may have influenced his story "The Suicide of Kiaros", first published in the literary journal The White Elephant. A fellow clerk one day was found locked in a store room dead, probably from suicide.  Baum could never stay away long from the stage. He performed in plays under the stage names of Louis F. Baum and George Brooks. In 1880, his father built him a theater in Richburg, New York, and Baum set about writing plays and gathering a company to act in them. The Maid of Arran proved a modest success, a melodrama with songs based on William Black's novel A Princess of Thule. Baum wrote the play and composed songs for it (making it a prototypical musical, as its songs relate to the narrative), and acted in the leading role. His aunt Katharine Gray played his character's aunt. She was the founder of Syracuse Oratory School, and Baum advertised his services in her catalog to teach theater, including stage business, play writing, directing, translating (French, German, and Italian), revision, and operettas.  On November 9, 1882, Baum married Maud Gage, a daughter of Matilda Joslyn Gage, a famous women's suffrage and feminist activist. While Baum was touring with The Maid of Arran, the theater in Richburg caught fire during a production of Baum's ironically titled parlor drama Matches, destroying the theater as well as the only known copies of many of Baum's scripts, including Matches, as well as costumes.  In July 1888, Baum and his wife moved to Aberdeen, Dakota Territory where he opened a store called "Baum's Bazaar". His habit of giving out wares on credit led to the eventual bankrupting of the store, so Baum turned to editing the local newspaper The Aberdeen Saturday Pioneer where he wrote the column Our Landlady. Following the death of Sitting Bull at the hands of Indian agency police, Baum urged the wholesale extermination of all America's native peoples in a column that he wrote on December 20, 1890 (full text below). On January 3, 1891 he returned to the subject in an editorial response to the Wounded Knee Massacre:  The Pioneer has before declared that our only safety depends upon the total extirmination  [sic] of the Indians. Having wronged them for centuries, we had better, in order to protect our civilization, follow it up by one more wrong and wipe these untamed and untamable creatures from the face of the earth.  A recent analysis of these editorials has challenged their literal interpretation, suggesting that the actual intent of Baum was to generate sympathy for the Indians via obnoxious argument, ostensibly promoting the contrary position.  Baum's description of Kansas in The Wonderful Wizard of Oz is based on his experiences in drought-ridden South Dakota. During much of this time, Matilda Joslyn Gage was living in the Baum household. While Baum was in South Dakota, he sang in a quartet which included James Kyle, who became one of the first Populist (People's Party) Senators in the U.S.

Using a quote from the above article, answer the following question: What did he work on after that?
At 20, Baum took on the national craze of breeding fancy poultry.