Why do you have to use a coffin to be buried in the U.S?

In the U.S., using a coffin for burial is primarily dictated by legal, cultural, and practical considerations. Many states have regulations that require a casket for burial to ensure the dignity and protection of the body. Caskets also provide structural integrity for the grave and prevent soil erosion. Additionally, cultural norms often dictate that funerals involve caskets as part of the mourning process.