REMOVE

1. Timeline
2. Historical
3. Europe
4. United States

WHAT

1. Data Visualization (6)
2. Historical Atlas (6)

WHERE

1. Canada (6)
2. Mexico (6)

WHO

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

WHEN

1. 1842 (6)