And okay, the mannequin is kind of creepy on this one, but I love the outfit. This is typical dress attire for a man in the 1850s: dinner coat with tails, cravat, linen trousers, silk hat.
In America (the clothing here is British), after the Civil War, a lot of color in dress attire for men was not especially fashionable. Black and white was the mode of the day (or evening, I should say), with the tuxedo taking over, more or less completely for a while. Prior to that, men's clothing was still colorful (and interesting!). This is perhaps part of why I like this decade in particular. Colors after the war were not unheard of, just not the norm.
Love the mannequin's crazy coiffure. Good decade for clothes, bad for hair.
This awesome picture comes from the awesome collection at the Victoria & Albert Museum.