1564 - William Shakespeare (baptised)
Shakespeare's birth date isn't actually known (although it's commonly celebrated on April 23rd), but he was baptized in Stratford-upon-Avon on April 26th.
1785 - John James Audubon
French-American ornithologist and painter, known for his book The Birds of America.
1889 - Anita Loos
American author ad screenwriter best known for her comic novel Gentlemen Prefer Blondes, and the movie it spawned.
1889 - Ludwig Wittgenstein
Austrian-British philosopher who worked in logic, mind and language.
1898 - Vincente Aleixandre
Spanish poet, winner of the 1977 Nobel Prize for Literature "for a creative poetic writing which illuminates man's condition in the cosmos and in present-day society, at the same time representing the great renewal of the traditions of Spanish poetry between the wars."
1912 - A.E. van Vogt
American "Golden Age" science fiction writer.
1914 - Bernard Malamud
American novelist, popularly best known for the book The Natural and it's film adaptation.
1935 - Patricia Reilly Giff
American children's author, two-time Newbery Honor winner.
1946 - Marilyn Nelson
American poet and children's author.
1966 - Natasha Trethewey
American poet; U.S. Poet Laureate since 2012 and 2007 Pulitzer Prize winner.
1910 - Bjørnstjerne Bjørnson
1926 - Armstrong Sperry
1991 - A.B. Guthrie Jr.
2004 - Hubert Selby Jr.