It is claimed that Block was never married in his life. His nationality was American and he had mixed ethnicity.
When Block was aged 11, he joined Art Institute of Chicago. While he was in his high school, he was nicknamed as Herblock. He completed his high school graduation in 1927 and then he joined Lake Forest College. He studied there for about two years. While in high school and college, he desired to be a cartoonist. There he did several cartoons and submitted that cartoon to Evanston News-Index. He was hired by Chicago Daily News' and then he quit his higher education. In 1933, he joined Newspaper Enterprise Association as the staff cartoonist. In 1942, he joined US Army where he did cartoons and press releases. He worked there for about two years and received his honorable discharge in 1944. Later on he was hired by The Washington Post as its chief editorial cartoonist and he worked there till his death. He died at the age of 81 in Washington, D.C., United States. His net worth was unknown.