Born and raised in Kings Mills, Ohio, Alcorn was assigned male at birth and grew up in a family affiliated with the Churches of Christ movement.

In her suicide note, Alcorn cited loneliness and alienation as key reasons for her decision to end her life and blamed her parents for causing these feelings.

Alcorn used Tumblr's queue feature to publish her suicide note online several hours after her death, and it soon attracted international attention across mainstream and social media.

Petitions were formed calling for the establishment of "Leelah's Law", a ban on conversion therapy in the United States, which received a supportive response from then-president Barack Obama.

I immediately told my mom, and she reacted extremely negatively, telling me that it was a phase, that I would never truly be a girl, that God doesn't make mistakes, that I am wrong.

According to her note, she immediately informed her mother, who reacted "extremely negatively" by claiming that it was only a phase and that God had made her a male, so she could never be a woman.

[2] Aged 16, she requested that she be allowed to undergo transition treatment, but was denied permission: in her words, "I felt hopeless, that I was just going to look like a man in drag for the rest of my life.

"[2] Alcorn publicly revealed her attraction to males when she was 16, as she believed that identifying as gay at that point would be a stepping stone to coming out as a transgender at a later date.

[2] At the end of the school year, they returned her mobile phone to her and allowed her to regain contact with her friends, although by this time, according to Alcorn, her relationship with many of them had become strained, and she continued to feel isolated.

[2] Two months before her death, Alcorn sought out help on Reddit, asking users whether the treatment perpetrated by her parents constituted child abuse.

It contained conversations showing that she had planned to jump off the bridge that crosses Interstate 71 days before the incident, but then contacted a crisis hotline and, as told to a friend, "basically cried [her] eyes out for a couple of hours talking to a lady there".

[2]She expressed her wish that all of her possessions and money be donated to a transgender advocacy charity,[2] and called for issues surrounding gender identity to be taught in schools.

"[2][10][18] A second post appeared shortly after; titled "Sorry", it featured an apology to her close friends and siblings for the trauma that her suicide would put them through, but also contained a message to her parents: "Fuck you.

"[2][19][20] An additional, handwritten suicide note reading "I've had enough" was found on her bed, but then thrown away by Alcorn's mother after police made a copy.

[26] On Twitter, American LGBT rights activist Dan Savage argued that Alcorn's parents should be prosecuted for their role in bringing about their daughter's death, commenting that through their actions they "threw her in front of that truck".

[27][28][29] He added that legal action should also be brought against the conversion therapists who had counseled Leelah, and suggested that the Alcorns should lose custody of their other children.

[32] People magazine quoted Johanna Olson, Medical Director for the Center of Trans Youth Health and Development at Children's Hospital Los Angeles, as stating that "Did Leelah's parents love her?

[10][11][12] By December 30, Alcorn's death had attracted worldwide attention;[11] news outlets across the world had picked up the story, and the hashtag #LeelahAlcorn had topped Twitter.

"[33] On January 1, 2015, the Cincinnati-based LGBT rights group Support Marriage Equality Ohio hosted a vigil for Alcorn outside Kings High School.

[34] A further vigil was organized by both The Diverse City Youth Chorus in partnership with the Cincinnati chapter of the Gay, Lesbian and Straight Education Network at the Clifton Cultural Arts Center for January 10.

[44] Among the transgender celebrities who publicly responded to the incident were Janet Mock, Andreja Pejić, and Laverne Cox,[45][46] while the musician Ray Toro released a song, "For the Lost and Brave," in dedication to Alcorn.

[50] In June 2015, the singer Miley Cyrus founded the Happy Hippie Foundation, an organization to raise awareness of homelessness and LGBT issues among young people, partly in response to Alcorn's death.

[52] After reading about Alcorn's death, British musician Declan McKenna was inspired to write a song, "Paracetamol," which was included on his debut album What Do You Think About the Car?

[54] Carolyn Washburn, editor of the Ohio newspaper The Cincinnati Enquirer, stated that the incident "raises important issues we hope will prompt conversations in families throughout our region.

[55] When contacted by The Cincinnati Enquirer, Shane Morgan, the founder and chair of transgender advocate group TransOhio, stated that while 2014 witnessed gains for the trans rights movement, Alcorn's death illustrated how "trans people are still being victimized and still being disrespected", highlighting the high rate of transgender people who had been murdered that year.

"[30] Allison Woolbert, executive director of the Transgender Human Rights Institute, informed The Independent that Alcorn's case was "not unique"; the newspaper highlighted research from the US Centers for Disease Control and Prevention indicating that LGBT youth are about twice as likely to attempt suicide than heterosexual, cisgender teenagers.

[46] Kevin Jennings of the Arcus Foundation also situated Alcorn's death within wider problems facing young LGBT people.

[36] On January 6, Adam Hoover of Marriage Equality Ohio remarked that, since the request of having Alcorn's chosen name on her gravestone seemed "like a slim possibility", they would be raising money for a permanent memorial arranged as a bench, tree and commemorative plaque.

"[62] As of December 2018, the "Leelah Alcorn Highway Memorial" group continued to meet four times a year to clean that stretch of road.

[71][72][73] In December 2015, Cincinnati became the second U.S. city after Washington, D.C., to ban the practice of conversion therapy outright; council member Chris Seelbach cited Alcorn's suicide as an influence in the decision and stated that "she challenged us to make her death matter, and we're doing just that.