In the 1800's, immigrants from the Rhine region of Germany migrated to Southeastern Pennsylvania. These people included Amish, Mennnonite and Lutherans, who eventually became known as the Pennsylvania Dutch. Naturally, these settlers brought their old world dress, language and traditions to Pennsylvania with them.
The bright patterns and geometric forms, were used by the ancestors of the Pennsylvania German settlers on birth certificates, family Bibles, furniture, pottery, textile, etc. Many are thought to have orginated from religious motif designs. It is a misunderstanding of the "English" that classifies the Pennsylvania "Dutch" and the hex sign as "Amish". The Pennsylvania "Dutch" are a diverse community of religious beliefs and lifestyles of which the Amish belong.
Amish and Mennonites were known as people of "plain" dress. Lutherans and other Reformed groups of more worldly dress were called "fancy". Over time, these people became known as "Pennsylvania Dutch". Hex signs on buildings were used by the "Fancy Germans" mainly of the Lutheran Faith. These very colorful symbols had meanings based on color and design. The signs were meant to protect (or place a "hex" on) the structures and things inside of them from evil and misfortune. The Plain or Pietist Germans include members of the Old Order Amish who do not use Hex Signs. While the Amish make hex signs for the "English", they have never been used by the Amish.
Today Hex signs fascinate us as we drive by them or even go on a hex sign tour. Many locals still place hex signs in and around their homes for decorative reasons and for simply "good luck".