[9]More recent dumbwaiters can be more sophisticated, using electric motors, automatic control systems, and custom freight containers characteristic of other kinds of elevators.
[10] Recently constructed book lifts in libraries and mail or other freight transports in office towers may be larger than many dumbwaiters in public restaurants and private homes, supporting loads as heavy as 450 kg (1000 lbs).
[2] Modern dumbwaiters in the United States and Canada must comply[citation needed] with American Society of Mechanical Engineers (ASME) codes and, therefore, have features similar to those of passenger elevators.
Margaret Bayard Smith wrote that former U.S. President Thomas Jefferson had kept dumbwaiters at both the White House and his Monticello estate whenever she visited him at both places.
[12] She also wrote that these dumbwaiters were built to reduce the number of servants required near dining rooms, allowing more privacy in conversations which might include sensitive information.
[12] After defecting from the Soviet underground in 1938, Whittaker Chambers gave a stash of stolen documents to his nephew-in-law, Nathan Levine, who hid them in a dumbwaiter in his mother's house in Brooklyn.