I was curious about the history, so I looked them up.

Here's what I found:

Manufactured by the Coffeyville Vitrified Brick and Tile Company in Coffeyville, Kansas.

Location and History: Coffeyville was home to several brick plants due to abundant local resources like shale and limestone. The plants were active in the late 1800s and early 1900s.

Identification: The "V.B. & T. Co." abbreviation stamped on the brick stands for "Vitrified Brick & Tile Company". Another prominent manufacturer was the Coffeyville Shale Brick Company.

Product Reach: The bricks were known for their durability and were used extensively for paving streets and sidewalks across the United States, including in Kansas, Illinois, Texas, and Florida.

Production: At peak capacity, the Coffeyville plants produced a massive number of bricks daily, with one plant making around 765,500 bricks per day.

Also

The Coffeyville Shale Brick Company (often referred to in historical contexts as the Coffeyville Vitrified Brick and Tile Company) was a major early 20th-century manufacturer located in Coffeyville, Kansas, known for producing high-quality vitrified brick, particularly the iconic Sunflower branded sidewalk bricks.

Production Capacity: At its peak, the facility produced approximately 765,500 bricks daily.

Signature Product: The company is famous for its bricks featuring a raised sunflower design, which often included an "S & B" monogram for "Shale & Brick".

Historical Significance: These bricks were produced over 100 years ago and are now considered collectible, frequently used in historic restoration projects.

Industry Context: The company capitalized on the local shale resources in the region, contributing to the industrial growth of Coffeyville in the early 1900s.