31 янв 1830 г. - TIMELINE KEY

Описание:

Purple items are items which pertain strictly to the life of John Muir

Blue items pertain to significant advancements in the field of natural preservation or scientific advancement

Green items pertain to events which involve the political and historical climate of the United States

Red items pertain to the death of presidents while still in office. (there are quite a few during this time period)