The dress code in Atlantic City is mainly casual, but it wasn't always casual. One hundred years ago people got all dressed up to walk on the Atlantic City Boardwalk. They also covered themselves to go on the beach. See photos below.

Postcard by M. B. Smith - from the collection of Thomas Topham.
No casual dressers seen in this group.

Photoby Detroit Publishing Company - from the Library of Congress.
Bathing Beauties 1880 - 1920. Not much skin showing.

Photo from the Robert Dennis Collection 1850 - 1920 - Library of Congress
It wasn't just the women who had to cover up, the men also had to cover up.
But not the dog.
Thomas Topham -1951