Birthdays
William Augustus Hall
Turns 45 on this date
Charles F. Mayer
Turns 65 on this date
Irvin McDowell
Turns 42 on this date
John Brown Parker
Turns 44 on this date
Haldimand Sumner Putnam
Turns 25 on this date
George Philip Rhinehart
Turns 30 on this date
Thomas Lafayette Rosser
Turns 24 on this date
Henry Harrison Walker
Turns 28 on this date
Events
| US/the World | Garibaldi states that the former Bourbon Kingdom of the Two Sicilies will now form part of a united Italy | 10/15/1860 |
| US/the World | In Sicily, announcement of a popular plebiscite in former Neapolitan provinces on joining a united Italy | 10/15/1860 |
| US/the World | Prince Albert pays a visit to the United States Military Academy | 10/15/1860 |
Documents
| Letter | Grace Bedell to Abraham Lincoln, October 15, 1860 | 10/15/1860 |
| Newspaper | New York Times, “Very Suspicious,” October 15, 1860 | 10/15/1860 |