New York once sent letters beneath the streets at about 35 miles an hour.

Compressed air pushed mail-filled canisters through tubes between post offices.

Above ground, traffic crawled. Below, hundreds of letters could travel together in a capsule.

Letters once raced through tunnels beneath New York

An archival photograph of pneumatic mail machinery and workers in a post office basement

An archival photograph of pneumatic mail machinery and workers in a post office basement — Smithsonian National Postal Museum

A cylindrical pneumatic mail canister from the National Postal Museum collection

A cylindrical pneumatic mail canister from the National Postal Museum collection — Smithsonian National Postal Museum

An archival map of pneumatic tube routes connecting New York City post offices

Letters once raced through tunnels beneath New York

Explore related topics