Birthdays
Thomas Ward Custer
Turns 21 on this date
Robert Carlos De Large
Turns 24 on this date
James Henry Hackett
Turns 66 on this date
Jeremy Clarke Hagey
Turns 31 on this date
John Edwin Reagan
Turns 12 on this date
Events
| Campaigns/Elections | In Indianapolis, angry Indiana Democrats condemn Congress and support President Johnson. | 03/15/1866 |
| Campaigns/Elections | In Indianapolis, the Indiana Democratic Party holds its state convention | 03/15/1866 |
| US/the World | Spain signs a treaty confirming the independence the Republic of Honduras had won in 1821. | 03/15/1866 |
| Campaigns/Elections | Susannah Evans, the famous Welsh teenage temperance advocate, speaks in Chicago, Illinois | 03/15/1866 |
| Legal/Political | The first session of the 39th Congress is sitting in Washington DC from early January to late July, 1866 |
01/07/1866 to 07/27/1866 |