Built on the hulls of cancelled battlecruisers, Lexington-class aircraft carriers were the first built, by the United States Navy, intended for fleet operations rather than experimentation. USS Langley (CV-1) was experimental.
There were two ships in the class, USS Lexington (CV-2)' and USS Saratoga (CV-3). Lexington was sunk at the Battle of the Coral Sea; the worn-out Saratoga was used as a target ship at postwar nuclear weapon tests.
The ships displaced 33,000 tons, were 901 feet long, and had a beam of 112 feet and an average draft of 32 feet. 8" naval guns were originally installed but later removed; they were intended as a last-ditch defense after the flight deck was destroyed. The flight deck was straight, as in other WWII carriers. Most takeoffs did not use catapults, but the ships did have catapults, using flywheels rather than the compressed air of the Langley.
When launched, they had a minimal antiaircraft gun fit, which was improved as time permitted — little time in the case of the Lexington.