The words that come to mind are 'quality control' , when it comes to 19th century bricks .
There's plenty of high-quality 19th century bricks still in buildings in the U.S. , as well as superior quality pavers still in use (dry pressed) .
I've found some locally/regionally produced bricks that had quality ranges from "oh my God!' to 'what were they thinkin' ... especially in areas with clay and limestone geology .
Sometimes these local manufacture sites would make their first 'production run' to build kilns for either limestone or clay bricks ( and sometimes had to be rebuilt/demolished due to low quality) .
The standards for some of these makers seemed to me to be , by-and-large , self-regulated .
Uniform Building Codes were often bypassed , or nonexistent (payola & expediancy were often factors) during 19th & early 20th centuries ( think : San Francisco Fire , Great Chicago Fire ) in cities and rural areas .
Terra cotta manufacturers had similar problems ; many sprang up for city buildings & vanished into obscurity .
On the West coast , there's lots of examples of masonry workers being brought over from Turkey & Morrocco for specific building projects (they were profoundly cheap workers , and often really great artisans) . They'd bring their native/regional skills along with them , and had methods that were both outstanding and shabby .
By the amount of aggregate in the brick photo you posted (perhaps glacial till or river-gravel?) , yours looks like a fired mud-brick .
Since it's got the 'algae patina' and is water worn it's kinda tough to tell , though .
With the Westward expantion of the U.S. , buildings were often really hurry-up affairs for the common man , who usually could not afford to have materials shipped in from more established areas : they used what was available locally .
Lots of history in them bricks !
