Until you can acquire a pair of reproduction trousers, this modified pants project will get you out to the first reenactment or two in a reasonable approximation of period style. Some types of modern pants
can be made over into period-looking trousers with a minimum of adjustments and sewing. This is one of the easier modification projects we have, so fear not-you can do this!
The hardest part is the search for the basic pant. At your local thrift shop, peruse the pants section. Don't even look at the jeans, you want to examine the "suit" types of slacks. Buy slacks one size larger, or at least in a style that fits loosely in the seat and leg. Try to find pants with NO back pockets, or at least with patch pockets that can be removed. Search for fabrics in dull colors, in wool, wool blend, or a homespun-looking cotton fabric. Period pants did not have front pleats, so avoid them.
Remove all belt loops from the pants. Remove any back pockets.
Split the rear seam down about 3-4 inches.
Cut a hole on each side of the rear waistband, then insert a leather lace to secure/adjust the waistband. Finishing the holes with a buttonhole stitch will prevent ripping/raveling.
Sew buttons to the waistband where needed to attach braces.
Unfortunately, modern pants will have a zipper fly. If you are ambitious, you can remove the zipper and add buttons and buttonholes. If not, try to conceal the zipper fly with a vest or coat.
Courtesy of Fannie and Vera's