REMOVE

1. Historical
2. Data Visualization
3. Canada

WHAT

1. Historical Atlas (6)
2. Timeline (6)

WHERE

1. Europe (6)
2. Mexico (6)
3. United States (6)

WHO

1. Boynton, G. W. (6)
2. Holgate, Jerome B., 1812- … (6)
3. J.B. Holgate (6)

WHEN

1. 1842 (6)