Much of the chatter going into the Oscars was about the lack of diversity in the Academy's choices, specifically the dearth of nominations for "Selma."
But while there were plenty of references to racial justice during the ceremony - drawing tears from the movie's David Oyelowo at one point - issues mentioned in acceptance speeches ranged from suicide to Alzheimer's and Lou Gehrig's disease to wage equality for women.
Sean Penn raised eyebrows with a reference he made to green cards in presenting the Oscar for best picture to Alejandro Gonzalez Inarritu for "Birdman," but the two are friends and Inarritu interpreted the comment as a joke.
"Who gave this son of a bitch his green card?" Penn said.
Inarritu, who is Mexican, hugged Penn warmly, and joked that the U.S. government might now impose immigration rules on the academy: "Two Mexicans in a row, that's suspicious." Alfonso Cuaron, another Mexican director, won for "Gravity" last year.
On a serious note, he said, he hoped the "latest generation of immigrants ... can be treated with the same dignity and respect of the ones who came before and built this incredible immigrant nation."
ALS AND ALZHEIMER'S
In accepting the award for best actress for "Still Alice," Julianne Moore said the movie shines a light on Alzheimer's, saying, "People with Alzheimer's deserve to be seen." She also noted that Richard Glatzer, who directed and wrote it with Wash Westmoreland, has ALS, also known as Lou Gehrig's disease.
Eddie Redmayne, accepting the best actor award for his portrayal of Stephen Hawking in "The Theory of Everything," said: "This Oscar belongs to all of those people around the world battling ALS."
Graham Moore, who won the Oscar for best adapted screenplay for "The Imitation Game," said in his acceptance speech that he had tried to kill himself as a teenager.
"When I was 16, I tried to kill myself because I felt weird and I felt different and I felt like I did not belong," he said. "I would like this moment to be for the kid out there who feels like she's weird and different and feels like she doesn't belong. ... Yes, you do."
Backstage, Moore said he saw the public moment as a rare opportunity for a writer and figured that "I might as well use it to say something meaningful."
Earlier in the ceremony, Dana Perry mentioned that her son had killed himself. Perry made her comments in accepting the Oscar for best documentary for "Crisis Hotline: Veterans Press 1."
"We should talk about suicide out loud," she said.
DEMOCRACY AND CITIZENFOUR
Laura Poitras used part of her speech accepting the award for best documentary for "Citizenfour" to note that "the disclosures that Edward Snowden reveals don't only expose threats to our privacy but to our democracy."
But when the camera went back to Oscar host Neil Patrick Harris, he was quick to make a reference to the controversy surrounding Snowden: "The subject of 'Citizenfour' couldn't be here for some treason."
Snowden is living in Russia to avoid arrest here. His supporters think he's a hero; critics think he's a traitor.
WAGE EQUALITY AND MORE ROLES FOR WOMEN
Meryl Streep leapt to her feet cheering, pointing and shouting, "Yes! Yes!" as Patricia Arquette ended her Oscar acceptance speech with a call for women's rights.
"To every woman who gave birth to every taxpayer and citizen in this nation: We have fought for everybody else's equal rights. It's our time to have wage equality in the U.S.," said Arquette, who won best supporting actress for portraying the mother in "Boyhood."
The movie "Wild" didn't win anything, but its two nominees, Reese Witherspoon and Laura Dern, also talked about women needing better representation in Hollywood on the red carpet before the show.
Witherspoon said she started her own production company, making "Gone Girl" and "Wild" because she "got frustrated" with roles available to women. Dernsaid she was "proud" along with Witherspoon to be among "two of the 47 women nominated tonight. May we see that number double."
LIMITED GLORY FOR SELMA
"Selma," the movie about Martin Luther King Jr.'s civil rights march in Selma, Alabama, 50 years ago, was only nominated in two categories, best picture and best song. Fans felt it deserved more recognition and that Oyelowo, who played King, had been passed over for best actor.
The movie lost best picture to "Birdman" but won best song after a stirring performance of the anthem "Glory" by Common and John Legend. The audience was on its feet for the performance, and Oyelowo's face was stained with tears.
The performance included a recreation onstage of the Edmund Pettus Bridge, where the original march took place.
"This bridge was once a landmark of a divided nation but is now a symbol for change," Common said while accepting the award. "This bridge was built on hope, welded with compassion."
Legend cited voting rights and the incarceration rates of black men. Backstage, he said, "When you think about equality and freedom and justice, we've got more work to do."
Take a look at the red carpet looks from this year's Oscars:
Academy Awards Oscars 2015 Red Carpet
Oscars speeches filled with political activism, pet issues
Scarlett Johansson opted for an emerald gown with a matching statement necklace. (Photo by Kevin Mazur/WireImage)
Lady Gaga made a statement in a thick white gown and winged red gloves. (Photo by Kevin Mazur/WireImage)
Wowzas! Julianne Moore looked drop-dead gorgeous in a form-fitting white sequined gown with elegant applique details. (Photo by Kevin Mazur/WireImage)
Best actor nominee Eddie Redmayne has been killing it this award season style-wise. The "Theory of Everything" star was stylish in a navy tux beside. His wife Hannah Bagshawe stunned in an intricate gown with a Grecian silhouette and ethnic details. (Photo by Kevin Mazur/WireImage)
Mom-to-be Keira Knightley looked straight out of a fairytale in a pretty embroidered gown and natural curls. (Photo by Kevin Mazur/WireImage)
Kerry Washington was absolutely flawless in a chic white gown with a satin bodice and textural skirt. (Photo by Kevin Mazur/WireImage)
"American Sniper" leading man Bradley Cooper looked smokin' in a three-piece tux. (Photo by Steve Granitz/WireImage)
"American Sniper" actress Sienna Miller always owns the red carpet. The stylish starlet wowed in a stunning gown with intricate ribbing and laser-cut details. (Photo by Jason Merritt/Getty Images)
Jared Leto stuck to his personal style in a light gray tux and white shoes. (Photo by Kevin Mazur/WireImage)
Lupita Nyong'o channeled old Hollywood glam in a sexy white gown and flawless makeup. (Photo by Jason Merritt/Getty Images)
"Gone Girl" actress Rosamund Pike was red-hot in a sexy crimson lace gown that highlighted her tiny waist. (Photo by Jeff Vespa/WireImage)
Naomi Watts turned heads in an eye-catching printed gown and purple lips. (Photo by Kevin Mazur/WireImage)
Can you believe Zoe Saldana just had twins? The new mom was glowing in a figure-hugging pink gown and elegant jewels. (Photo by Jason Merritt/Getty Images)
Emma Stone stunned in a gold beaded gown and red lips. (Photo by Steve Granitz/WireImage)
Style maven Marion Cotillard stunned in a unique, white perforated gown cinched in below the waist. (Photo by Jason Merritt/Getty Images)
Margot Robbie from "The Wolf of Wall Street" walked the red carpet in a robe-like draped Saint Laurent gown with sheer sleeves. Red lips and a vintage-inspired necklace completed her sexy look. (Photo by Kevin Mazur/WireImage)
Giuliana Rancic was ready to work the red carpet in a red-hot gown with stunning floral appliques. (Photo by Steve Granitz/WireImage)
Best actor nominee and "Birdman" star Michael Keaton looked dapper in a black tux. (Photo by Kevin Mazur/WireImage)
Jessica Chastain channeled old Hollywood in a super glam navy gown with a cowl neck. (Photo by Kevin Mazur/WireImage)
Ryan Seacrest opted for a classic black tux. (Photo by Jason Merritt/Getty Images)
Melanie Griffith, 57, showed off her hot bod in a form-fitting black gown, simple updo and sparkly clutch. (Photo by Jason Merritt/Getty Images)
Roshumba Williams opted for one of this season's hottest colors -- red. (Photo by Steve Granitz/WireImage)
"Boyhood" actor Ethan Hawke looked classy in a tuxedo beside his wife, Ryan, who sparkled in a sequined gown. (Photo by Jason Merritt/Getty Images)
Cate Blanchett looked sophisticated in a simple black gown and turquoise necklace. (Photo by Kevin Mazur/WireImage)
Michael Strahan looked totally handsome in a gray three-piece suit and smiled for the cameras. (Photo by Frazer Harrison/Getty Images)
Black Eyed Peas frontman Will i Am, 39, strayed from the usual tuxedo dress code and donned a funky black and white getup. (Photo by Jason Merritt/Getty Images)
Envy-inducing couple Adam Levine and Behati Prinsloo nabbed the spotlight on the red carpet. The Maroon 5 lead singer went for a simple black tux, and let his wife shine. The Victoria's Secret model wowed in a speckled black and red number and gunmetal accessories. (Photo by Kevin Mazur/WireImage)
Actress Katie Cassidy looked gorgeous in an ethereal embroidered gown in a stunning champagne color. (Photo by Kevin Mazur/WireImage)
John Stamos just keeps getting better with age! The actor smoldered in a black tux and red pocket square. (Photo by Kevin Mazur/WireImage)
Model Dorith Mous opted for a dramatic red number. (Photo by Michael Buckner/WireImage)
"Hunger Games" actor Josh Hutcherson was handsome in a simple black tux and perfectly-groomed coif. (Photo by Steve Granitz/WireImage)
"How to Get Away With Murder" actor Matt McGorry changed things up with a tweed jacket. (Photo by Jeff Vespa/WireImage)
Wild for blue! Thea Andrews went for this classic strapless number. (Photo by Steve Granitz/WireImage)
TV personality Keltie Knight chose a sexy gown with a thigh-high slit. (Photo by Steve Granitz/WireImage)
TV personality Louise Roe wowed in a blue printed gown with a full structural skirt. (Photo by Jason Merritt/Getty Images)
Jennifer Hudson flaunted her rockin' bod in a canary yellow column dress with a skinny metal belt. (Photo by Kevin Mazur/WireImage)
Robin Roberts dazzled in a ruby-red sequined T-shirt gown. (Photo by Kevin Mazur/WireImage)
Nancy O'Dell elongated her statuesque figure in a sexy black mermaid gown with a structural shoulder accent. (Photo by Jason Merritt/Getty Images)
Kelly Osbourne brought the drama in a theatrical gown with a lace bodice and full cascading skirt. (Photo by Jason Merritt/Getty Images)
Mario Lopez was ready for the night in a black tux and skinny tie. (Photo by Steve Granitz/WireImage)
TV personality Catt Sadler looked pretty in a nude and silver form-fitting gown and simple hair and makeup. (Photo by Jason Merritt/Getty Images)
Composer Mark Mothersbaugh and Anita Greenspan were all smiles in pink and black. (Photo by Frazer Harrison/Getty Images)
Production designer Maria Djurkovic and set decorator Tatiana MacDonald joined in on the fun in their black-tie best. (Photo by Ethan Miller/WireImage)
Songwriter Diane Warren strayed from the usual in black slacks, booties and a metallic tuxedo jacket. (Photo by Jason Merritt/Getty Images)
Nicole Kidman opted for a yellow-hue sequin gown with a red sash. (Photo by Jason Merritt/Getty Images)
Filmmakers Magda Hueckel and Tomasz Sliwinski coordinated in shades of blue. (Photo by Kevork Djansezian/Getty Images)
Shaun Robinson went for a sunny yellow gown and simple curls. (Photo by Lester Cohen/WireImage)
Kelly Ripa stunned in a shimmery black strapless gown with a full ballroom skirt. (Photo by Jeff Kravitz/FilmMagic)
Actress Genesis Rodriguez opted for a draped white gown with an elegant neckline. (Photo by Frazer Harrison/Getty Images)
Actor David Oyelowo opted for a nontraditional red tux.(Photo by Jeff Kravitz/FilmMagic)
"Boyhood" actor Ellar Coltrane looked dapper beside director Richard Linklater in matching black tuxes. (Photo by Frazer Harrison/Getty Images)
Young Hollywood's finest Chloe Grace Moretz looked stunning in a wheat-colored floral gown.(Photo by Kevin Mazur/WireImage)
"How To Get Away With Murder" star Viola Davis looked elegant in a cream-colored off-the-shoulder gown. (Photo by Kevin Mazur/WireImage)
Ava DuVernay showed off her personal style in a blue gown with Eastern-inspired bell sleeves. (Photo by Jason Merritt/Getty Images)
Gwyneth Paltrow looked gorgeous in a pink one-shoulder gown with a floral shoulder detail. A sleek ponytail and earrings completed the actress's modern look. (Photo by Jason Merritt/Getty Images)
Chris Pratt and Anna Faris sure clean up nice! The "Guardians of the Galaxy" star looked handsome in a tux, while his comedian wife dazzled in a shimmery ballroom gown. (Photo by Steve Granitz/WireImage)
HOLLYWOOD, CA - FEBRUARY 22: Actor Robert Duvall (R) and Luciana Duvall attend the 87th Annual Academy Awards at Hollywood & Highland Center on February 22, 2015 in Hollywood, California. (Photo by Steve Granitz/WireImage)
Oprah made an appearance in a sexy champagne gown. (Photo by Steve Granitz/WireImage)
Singer Solange Knowles wowed in a unique pantsuit. (Photo by Frazer Harrison/Getty Images)
Actor Chris Evans was a total hottie in a slim-fitting tuxedo. (Photo by Steve Granitz/WireImage)
Actress Andrea Riseborough opted for a simple yellow gown and feathered clutch. (Photo by Frazer Harrison/Getty Images)