George A. Romero, a horror visionary who created the modern zombie genre with his 1968 cult film, “Night of the Living Dead,” which has influenced generations of horror enthusiasts, died on Sunday in Toronto. He was 77.

His death came after “a brief but aggressive battle with lung cancer,” his family said in a statement.

“Night of the Living Dead,” made for about $100,000, was released when racial tensions were high in the United States. Mr. Romero had not intended to address that climate in the film, but with Duane Jones, a black man, as the lead, it was impossible to ignore the connection, Mr. Romero told NPR in a 2014 interview.

“We never thought of it being a racial piece at all, never,” he said. “But because the character was played by an African-American, you almost don’t notice anything else. We didn’t realize that. Duane did.”