What publishing house released Dr. Seuss's first children's book?

Dr. Seuss’s first children’s book was released by Vanguard Press. The book, “And to Think That I Saw It on Mulberry Street,” appeared in 1937 after many publishers rejected Geisel’s manuscript.

Geisel developed the story about Marco and his increasingly imaginative parade after inspiration from the rhythm of a ship’s engines. He submitted the manuscript under an earlier title and reportedly faced at least 20 rejections before meeting Mike McClintock, a former Dartmouth classmate who had become a juvenile editor at Vanguard.

Vanguard agreed to publish the book, launching Geisel’s career as a major children’s author. The book is specifically described as his first children’s book published under the name Dr. Seuss; he had previously illustrated collections of children’s school humor. Vanguard later published “The 500 Hats of Bartholomew Cubbins” as well.