(disclaimer: Many of the following passages are not my own words)
1968 – Tom of Finland’s Kake, a dark-haired, mustached leatherman. “Kake lived up to this moniker, a sort of post-Stonewall, hyper-masculine Johnny Appleseed traveling the world on his motorcycle to spread the seeds of liberated, mutually satisfying, ecstatically explicit gay sex. Kake’s international fans made him the template for what came to be known as the gay clone look of the 1970s. Between 1968 and 1986, Tom published 26 episodes of Kake adventures, most as 20-page booklets.”
1969? Rand Holmes had some early depictions of bisexual characters in the early Canadian underground tabloid, The Georgia Straight.
1970 – First gay kiss in Manga “In the Sunroom” by Keiko Takemiya
1971 – “Sandy Comes Out” by Trina Robbins in Issue 1, 1971 of Wimmen’s Comix
1972 – In Come Out Comix, Mary Wings tells the story of her realization that she was a lesbian and the process of coming out and forging new relationships. This groundbreaking book was the first comic book entirely about lesbianism.
1973 In Joyce Farmer and Lynn Chevlis Pandora’s Box comic had a lesbian character.
1974 – “Modern Romance” by Roberta Gregory in Wimmen’s Comix Issue 4
1976 – Dynamite Damsels After a couple of years of contributing to various underground comic anthologies (e.g., Wimmen’s Comix), Roberta Gregory self published her first one-artist comic book, Dynamite Damsels when she was 23 years old. The book is loaded with brief chapters loosely based on Gregory’s life as well as side stories featuring lesbian themes.(full format comic in full distribution)
1976 Gay Heart Throbs anthologies
1976 Howard Cruse’s character Headrack comes out in Barefootz
1976 Kaze to Ki no Uta/The Poem of the Wind and the Trees by Keiko Takemiya
1977 Pudge, Girl Blimp, by Lee Mars, has lesbian sex
1977 – Tits and Clits title became an anthology in Issue 4, creators contributed LGBT themed stories.
1978 – Dyke Shorts by Mary Wings (full format comic in full distribution)
1979 – Ralf König (born 8 August 1960) is one of the best known and most commercially successful German comic book creators. 1979, he came out as a gay man, and about this time he created short comics stories that appeared in the Munich underground magazine Zomix and the gay periodical Rosa Flieder.
1979/1980 – Gay Comix (later Gay Comics) is an underground comics series published from 1980–1998 featuring cartoons by and for gay and lesbian men and women. The comic books had the tagline “Lesbians and Gay Men Put It On Paper!”
1980s – Wendel by Howard Cruse
1981- Love and Rockets, featuring a bisexual and a lesbian character
1983 – Dykes to Watch Out For (sometimes DTWOF) was a comic strip by Alison Bechdel. The strip, which ran from 1983 to 2008, was one of the earliest ongoing representations of lesbians in popular culture
1984 – The Leonard & Larry characters first appeared in a 1984 issue of Gay Comix, then were later featured in The Advocate and Frontiers magazines. The comic series is collected in four volumes published by Palliard Press.
1986 – Meatmen: An Anthology of Gay Male Comics is a series of paperback books collecting short comics featuring gay and bisexual male characters. The comics included a mixture of explicit erotica and humor. Between 1986 and 2004, 26 black-and-white volumes of the series (160–200 pages each) were published by Leyland Publications, making it the longest-running anthology of gay male pornographic comics
1987 – Strip AIDS and Strip AIDS U.S.A. are comics anthology volumes published in 1987 in the UK, and 1988 in the US (respectively). They combined short comics with educational and sometimes comedic themes, to educate readers about HIV disease and safer sex, and to raise funds for the care of people with AIDS.
1991 Hothead Paisan: Homicidal Lesbian Terrorist is an alternative comic written and drawn by Diane DiMassa. It features the title character wreaking violent vengeance on male oppressors. Recurring characters include Hothead’s cat Chicken, her friend Roz, a talking lamp, and transgender love interest Daphne.
1991 – Robert Kirby had his first venture into producing comics with the comic zine Strange Looking Exile, which also featured work by Diane DiMassa, Roberta Gregory, Nick Leonard and Alison Bechdel. The zine ran from 1991 till 1994.
1991 – Butchy Butch appears in Roberta Gregory’s Naughty Bits
1992 Northstar, a Marvel Superhero, comes out – first mainstream gay superhero (I think)
1994 – Boy Trouble: Gay Boy Comics with a New Attitude edited by Robert Kirby and David Kelly emphasized personal stories and viewpoints outside the mainstream, with subject matter that ranged from sex, love, and longing to porn, drugs, and punk rock
1995 – Stuck Rubber Baby is a graphic novel by American cartoonist Howard Cruse (and editor of Gay Comix) Cruse’s first graphic novel after a decades-long career as an underground cartoonist, the book deals with homosexuality and racism in the 1960s in the southern United States in the midst of the Civil Rights Movement.
1997 – The Gay League is one of the first and largest groups in the world for LGBT comics fans.
2003 a small group of comics fans and professionals gathered together to form Prism Comics – an organization and website where LGBTQ and LGBTQ-friendly comics creators could network and share their comics and readers could find works that spoke directly to their experiences and lives.
2004 – Sexile/Sexilio by Jaime Cortez Published by Institute for Gay Men’s Health. This bilingual graphic novel tells the story of a Cuban exile who first thinks he’s gay, then realizes he’s really transgender.
2005 – Juicy Mother, edited by Jennifer Camper. Juicy Mother is a cartoon anthology with work by and about queers, women and people of color.
2006 – Fun Home by Alison Bechdel. t chronicles the author’s childhood and youth in rural Pennsylvania, United States, focusing on her complex relationship with her father. The book addresses themes of sexual orientation, gender roles, suicide, emotional abuse, dysfunctional family life, and the role of literature in understanding oneself and one’s family.
2010 Robert Kirby began his ongoing LGBT comics anthology THREE
2010 – Northwest Press is an American publisher specializing in LGBT-themed comic books and graphic novels. It was founded in 2010 by Charles “Zan” Christensen.
2010 First openly gay Archie charcter, Kevin Keller
2012 First mainstream superhero gay marriage (Northstar)
2012 Justin Hall edits No Straight Lines: Four Decades of Queer Comics, that took readers from the beginnings of LGBT comics history to the present day.
2012- Stripped: The Story of Gay Comics by Markus Pfalzgraf is published
2013 Robert Kirby edits QU33R which features queer comics legends as well as new talents.
2014 – Mari Naomi creates the Queer Cartoonist Database: http://queercartoonists.com/ LGBT Cartoonists of Color Database:
2014 – Pregnant Butch Nine Long Months Spent in Drag graphic memoir for anyone interested in the intersection of birth and gender
2014 Autostraddle is a progressively feminist online community for multiple generations of kickass lesbian, bisexual & otherwise inclined ladies Saturday Morning Cartoons: A segment where four artists take turns delighting you with their whimsy, facts and punchlines on Saturday mornings!
2015 – Queers & Comics Conference
Most of this info was found via oral history, wikipedia and google.