Originally Posted by Scissor Queen

One of the biggest reason 1/4 inch seams are used is the amount of additional fabric it would take over a whole queen size quilt. That extra quarter inch would probably add up to more than a yard of fabric on a queen size quilt.

Ironing seams to one side was done to keep the batting inside. Originally "batting" wasn't really batting. It was just hand fulls of carded cotton laid on the backing. That's also why really old quilts are heavily quilted.

Hand quilted quilts aren't quilted in the ditch as a rule either. They're quilted a quarter of an inch away from the ditch. In the ditch quilting was invented to hide machine quilting. Machine quilting was looked down upon until the last 15 years or so but it's been around for more than 100 years.