![](http://photos1.blogger.com/blogger/3135/2088/320/120px-Shaker_chair.0.jpg)
They reached their height of popularity at the time of the Civil War, when their numbers reached around 6000. The Shaker community declined afterwards, some historians opining that their homemade works could no longer compete in a marketplace fueled by the Industrial Revolution. There is only one original Shaker community left, which was founded in 1783; it's located in Maine and has its own website.
Shaker furniture is known for its clean, simple lines and construction, which conformed to the Shaker philosophy of cleanliness, order, and economy. "Hands to work, hearts to God," is the Shaker motto; one of their most popular songs is "Tis a Gift to Be Simple."
To view lots of reproductions of Shaker furniture designs, check out Woodworks. For more on the history of the Shakers, check Wikipedia.
Sources: DIY Network.com, SabbathdayLake, Funtrivia.com, ShakerWoodworks.