who invented LIncoln Logs?"?

Answer 1

Lincoln Logs were invented in 1916 by John Lloyd Wright (1892-1972), an architect and one of the five children of the world-famous architect Frank Lloyd Wright.

Answer 2

In the 1910s, American builders were busy on construction sites in the city and in the playroom. Introduced just after Tinkertoys and the Erector Set, Lincoln Logs were yet another construction toy to make it big during the decade. John Lloyd Wright, son of architect Frank Lloyd Wright, brought out the line of sturdy, interlocking logs in 1916. Wright claimed that the foundation of Tokyo’s earthquake-proof Imperial Hotel, which he saw while it was under construction, inspired the shape of his logs.
Lincoln Logs turned out to be a toymaker’s dream. The original sets were an instant success, and after World War II, sales of Lincoln Logs got another boost from the baby boom. The sets were popular among postwar parents because they were more sophisticated than plain building blocks but still challenged children’s powers of concentration and eye-hand coordination. Ironically, Lincoln Logs—long a favorite of proponents of educational toys—were among the first toys to be promoted on a television show, 1953’s Pioneer Playhouse. The ads targeted affluent parents, who were most likely to own a television set and to buy educational toys. Sometimes a toy that has had a previous life returns to catch the eyes of children at just the right moment in history.

Lincoln Logs are still on many people's short list of the most popular toys of all time.

Hope this info helped.