Ebert along with his movie partner, Gene Siskel, were the most influential film critics with their "At the Movies"/"Sikel & Ebert" television show that ran for seventeen years.
You can read more about his life and death at www.suntimes.com.
Reading Ebert's last article, posted April 2nd, I can tell that he knew his time was coming to an end.
"So on this day of reflection I say again, thank you for going on this journey with me. I'll see you at the movies."