Entertainment Harper Lee dead: Celebrities react to the 'To Kill a Mockingbird' author's passing By amNY.com Updated February 19, 2016 12:23 PM Print Share fbShare Tweet Email "To Kill a Mockingbird" author Harper Lee died on Feb. 19, 2016. She was 89 years old. Celebrities, politicians, writers and others expressed sadness over the passing of the acclaimed author. Piers Morgan called the 1960 book "one of the greatest books ever written." Katie Couric called it "a gift to us all." Scroll through to see how celebrities are honoring and mourning the beloved author. Reese Witherspoon Photo Credit: Getty Images / Jason Merritt The actress wrote on Twitter: "She revealed it all...the glory and the fear and the hate and the beauty. May she rest in peace. #HarperLee" Katie Couric Photo Credit: Getty Images / Jonathan Leibson "So sorry to hear about Harper Lee's passing. 'To Kill a Mockingbird' was a gift to us all," Katie Couric tweeted. Sophia Bush Photo Credit: Getty Images / Jason Merritt Actress Sophia Bush wrote on Instagram: "RIP Harper Lee. Thank you, thank you, thank you. #HarperLee #ToKillAMockingbird" Tim Cook Photo Credit: Getty Images / Andrew Burton "Rest in peace, Harper Lee. 'The one thing that doesn't abide by majority rule is a person's conscience,'" Apple CEO Tim Cook said on Twitter. Ava DuVernay Photo Credit: Getty Images / Kevork Djansezian The filmmaker quoted from "To Kill a Mockingbird" on Twitter: "'You never really understand a person... until you climb into his skin and walk around in it.' Thank you, #HarperLee." E.L. James Photo Credit: Getty Images / John MacDougall The "50 Shades of Grey" author tweeted: "RIP Harper Lee." Joe Scarborough Photo Credit: Getty Images / Larry Busacca "It is hard to overstate the impact of Harper Lee. I thank you as a reader, as a Southerner, and as an American," the MSNBC host said on Twitter. Susan Orlean Photo Credit: Getty Images / Joe Kohen The "Orchid Thief" author and New Yorker staff writer tweeted: "RIP Harper Lee and thank you." Piers Morgan Photo Credit: Getty Images / Ramin Talaie Journalist Piers Morgan tweeted: "RIP Harper Lee, 89. Author of one of the greatest books ever written. #ToKillAMockingBird" Chirlane McCray Photo Credit: Getty Images / Andrew Burton First Lady of New York City Chirlane McCray said on Twitter: "Mourning the loss of Harper Lee who stirred the minds & hearts of America with "To Kill A Mockingbird"." By amNY.com Share on Facebook Share on Twitter Comments We're revamping our Comments section. Learn more and share your input.