Cities and their Rivers
American Inventors
Medical Study
Famous Dogs
Centuries in History
100
Las Cruces, New Mexico
Rio Grande
100
Photography pioneer, invented paperback flexible film, the Kodak camera
George Eastman
100
Cardiology
Heart
100
Collie who saved his owner Timmy and Family from many near tragic experiences.
Lassie
100
Dropping of atomic bomb on Hiroshima and Nagasaki
20th century
200
St. Louis, Missouri
Mississippi
200
Phonograph
Thomas Edison
200
Skin
Dermatology
200
Blondie and Dagwood's dog
Daisy
200
Lewis and Clark made their expedition
19th century
300
Little Rock, Arkansas
Arkansas
300
Telegraph
Samuel Morse
300
Hematology
Blood
300
Little Orphan Annie's dog
Sandy
300
Earliest settlement in North America made in Florida
16th century
400
Albany, New York
Hudson
400
Sewing machine
Elias Howe
400
Neurology
Nervous System
400
Mickey Mouse's dog
Pluto
400
French-Indian War
18th century
500
Austin, Texas
Colorado
500
Arc lighting and incandescent lamp
Nicola Tesla
500
Otolaryngology
Eye, ear, throat
500
A cowdog who has his own book series
Hank
500
Magellan circumnavigated the world
16th century
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