Stonemasons, circa 1906, Fort Worth, Texas. Source: Hometownbyhandlebar.com.

The earliest American homes were built with stones gathered from open fields or unearthed while a farmer tilled his land. These stones were not shaped with tools, but cobbled together as-is, with mortar used to seal — and compensate for inconsistencies in stone shapes and sizes. The most smoothly faced stones were reserved for the exterior, front-facing sides of stone walls.

Once we had our footing in this new world, we refined the building process and quarried stones for home construction. Enter the stone mason. Once stone blocks were rough cut from the face of a rock quarry, the mason “dressed” or “faced” the stones to suit construction needs.

Wall types, clockwise from top left: Fieldstone, rubble and coursed rubble. Source: stone.poplarheightsfarm.org.

To rough-face a stone, the mason first used a mashing hammer to trim away any projections that would prevent the stone from being laid in a straight line. Next, following straight lines he marked with a square, the mason would fine tune his work by trimming away additional stone with a pitching tool and mallet. To smooth-face a stone, a pick was used in place of a pitching tool.

Once all that pounding, trimming and chiseling was done, wall height and width were staked out with string, mortar (a “mud” made by mixing together lime, sand, hair and water) was prepared, trenches were dug and stones set in place, using smaller stones (i.e. gallets) to fill voids between stones and mortar to set the work in place. One part skilled craftsman and one part artisan, the stonemason could envision a design, face stones and then set them in a tightly woven, incredibly intricate pattern that required little mortar to stay put.

Example of random-coursed rubble walls: James Mendenhall Mill, New Castle County, Delaware, circa 1826. Source: mchhistory.blogspot.com.

Rubble is probably the best example of early quarried and rough-faced stone. Rubbled stones retained their irregular shape and size, but required less mortar as they were precisely pieced together. Examples include random-coursed rubble, similar in appearance to a jigsaw puzzle, and regular-coursed rubble, which created continuous horizontal joints.

As masonry improved, rubble was replaced by tooled blocks that were used to build even-coursed walls. The stonemason would “sign” his artwork by chiseling his maker’s mark into an individual stone, cornerstone or lintel – a lasting reminder of his skill and craftsmanship.

Mason’s mark on quoin or cornerstone. Source: David Sankey.

Resources:
Masons and Bricklayers
Historic Stonework by William Kibbel III, The Home Inspector
Early American Architecture: From the First Colonial Settlements to the National Period by Hugh Morrison