Pattern for making leggings

[Stophel]

If one is of German or French extraction, full length, button up leggings/gaiters would be EXTREMELY common for ordinary civilian men to wear. The English, on the other hand, by the middle of the century anyway, adopted the short half-gaiter, reaching halfway up the calf/shin, and these likewise are very commonly seen on average working men. They definitely are not a military-only article.

 

[just4fun63]

Crazy Crow sells them. Not to expensive

 

[Ketchakah]

Spence' post is good. In the colonies, leggings for gentlemen followed the English pattern and buttoned on. Much like the taller British military pattern.

Frontier people tended to emulate the natives when in the woods and many adopted "Indian Dress" Leggings would be made like the local Natives did. Either side seam (most common) or front seem (Very regional specific)
The length of the "flap" varied dependent on maker. Some had NO flap, just a seam. Some were sewn some were laced. Some were just wrapped around the leg.

Making is easy. Measure from ankle to above knee. Measure loosely around top at thigh. Measure loosely around knee. Connect the dots and carry to the bottom. Done. You can taper the ankle if you want, but not too much or you wont get your foot thru.