- In May 1804, Meriwether Lewis and William Clark, America's most famous same-sex coupling, led 45 men up the Missouri River with the purpose of exploring the newly acquired lands of the Louisiana Purchase and the goal of reaching the Pacific Ocean. For gay and lesbian Lewis-and-Clark buffs, the recent speculation that Meriwether Lewis might have been gay has made an already fascinating story downright titillating.
- Nicholas Biddle, a member of the Lewis and Clark expeditions, records that among Minitarees (Indians) if a boy shows any symptoms of effeminacy or girlish inclinations he is put among the girls, dressed in their way, brought up with them and sometimes married to men. They are referred to as berdache or two-spirit.
- When the Missouri Territory was organized in 1812, it received all laws of Louisiana. The Louisiana sodomy law in force that it received used the common-law definition and established a penalty of life imprisonment.
- In 1816, the Missouri Territory enacted a law that adopted the English common law and English statutes in aid of the common law prior to the Jamestown settlement. A proviso of the law, however, was that no British criminal statutes were adopted. Another proviso limited the penalty for violation of a common-law crime to fine and imprisonment. The English common law provided death for sodomy.
- William Drummond Stewart, a member of the Scottish nobility, arrives in St. Louis to begin several years of travels to the far reaches of the unknown western frontier. According to the book "Men in Eden" by William Benemann, Stewart was gay. He would use St. Louis as a base for his "flamboyant" adventures.
- No change was made in the sodomy law until 1835 when a new code created the now state of Missouri’s first sodomy law that established a penalty of a minimum of ten years. This still allowed a sentence of life imprisonment, but no longer made it compulsory.
- Emma Conn Crow was born on 3 April 1839 in St Louis to philanthropist Wayman Crow and his wife, Isabella Buck Conn. As a nineteen-year-old fledgling actress, Emma began an affair with much older Charlotte Cushman, a famous stage actress who also was romantically invovled with former St. Louisan Harriet Hosmer. With her lover's encouragement, she married Edwin Charles "Ned" Cushman, Charlotte's nephew and adopted son, on 3 April 1861, in St Louis. Late in life, Emma penned, "Insight; A Record of Psychic Experiences: A Series of Questions and Answers Dealing with the World of Facts, the World of Ideals and the World of Real." Emma Crow Cushman died of pneumonia, 15 September 1920, aged 81.
- Omar Kingsley is born in St. Louis. He ran away to the circus when he was eight years old. He was trained in the dangerous trick-riding, and presented as a young woman named Ella Zoyara. Ella toured Europe with the circus. In Moscow, a Count, believing himself to be in love, offered a large sum of money to be introduced to her. In Italy the king, Victorio Emanuele II requested that she visit him. Ella did so but always accompanied by a female companion. Back in America, Omar married Sallie Stickney, a fellow circus rider. In Manila, several military officers accused Ella of not being a woman after she had refused one of them. This resulted in a brawl and Ella and the circus director were thrown into jail. Ella's 'true' sex was then discovered. Omar gave up his life as Ella to become a partner in the circus, but continued to give benefit performances. He died of smallpox in Bombay,
- A 1844 story by J. Field in The Reveille suggested that frontiersman Mike Fink was gay. A 1847 version of the story does not mention this.
- Lesbian Harriet Hosmer attends St. Louis Medical College. She became a noted sculptor. Among her public works in the city of St. Louis are the Senator Thomas Hart Benton statue in Lafayette Park, and “Beatrice Cenci” at the Mercantile Library at UMSL.
- Missouri's sodomy statutes went into effect in 1856, banning sexual intercourse between persons of the same sex.
- Shaw's Gardens (Missouri Botanical Gardens) opens to the public. Scholarly debate continues on whether lifelong bachelor and Garden founder Henry Shaw may have been gay.
- Charles Hamilton Hughes (1839-1916) begins to publish a St. Louis-based medical journal - The Alienist and Neurologist. The journal was published from 1880 until his death in 1916, making him the sole editor for all 37 volumes. The Journal would feature several groundbreaking reports on homosexuality.
- The earliest sodomy case in Missouri to receive publication (albeit in a medical journal) occurred in 1881. An 18-year-old male, James Smith, known as an "abandoned character," engaged in sodomy with a 13-year-old male. This was a crime that is "rarely brought to the knowledge of the public." The victim made no effort to notify police of the assault and it became known only because a police officer happened upon him as he was crying. The young man was reluctant to tell the police or a physician what had happened.
- The visit of Oscar Wilde, the famed Irish writer, poet and satirist to St. Louis in October 1882 was front page news. His celebrity was widely covered and the fascination with the openly gay man was reported in all the major newspapers of the day.
- Sara Teasdale is born. Noted for lesbian themes in her poetry.
- A vicious murder at Southern Hotel in St. Louis and subsequent trial makes front page headlines that mention a "peculiar relationship" between the victim and the accused murderer.
- A'Lelia Walker moves to St. Louis with her mother Sarah "Madame" Walker, the nation's first female millionaire. A'Lelia was either bi-sexual, a lesbian or a strong LGBT ally, further study is needed.
- Actress Cecil Cunningham is born in St. Louis. Noted for "lesbian" roles in movies.
- McClelland Barclay is born in St. Louis, and would become a well-known artist known for his homoerotic art in WW2 posters and advertising. His sexuality is unknown, but his art is very gay.
- Construction begins on the Wainwright Building. Noted architect Louis H. Sullivan led the design of this historic landmark - the first steel framed skyscraper in America. Debate continues on whether Sullivan may have been gay. He also designed the Wainwright tomb in St. Louis.
- Lillie Rose Ernst was one of the first twelve women to graduate from Washington University. She began her life-long teaching career at Central High School the next year. She never married. It is clear that she was devoted to her female friendships. She was especially close to author Leonora Halsted who left a $20,000 estate to Ernst in "appreciation of her devoted care...and my abiding love."
- On February 23, Dr. Charles Breedlove, a young dentist, commits suicide at Hurst's Hotel. The story makes national headlines due to his infatuation with his "friend" Issac Judson. Upon his death, Dr. Breedlove was wearing a charm around his neck featuring a picture of Judson.
- The St. Louis Post-Dispatch reports on "clique of perverts" who were meeting for male-male sex in a downtown office building.
- The Missouri Supreme Court upholds a conviction for assault to commit sodomy of a St. Louis police officer who attempted sodomy with another male.
- The Awakening by St. Louis author Kate Chopin is published, noted for its lesbian themes.