REMOVE

1. Data Visualization
2. Historical Atlas
3. Mexico

WHAT

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

WHERE

1. Canada (6)
2. Europe (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)