Pierce expanded his patent medicine business through creating and investing in a series of interlocking businesses from his ever-growing profit. He also invested in other business ventures.
Glass bottle production Pierce charged his son Valentine Mott Pierce with creating a source for the millions of glass bottles used in selling the company's many patent medicines. First leasing the Eagle Glass Works at Brockwayville, Pennsylvania in 1904, in 1905 son Pierce purchased the St. Marys Glass company at St. Marys, Pennsylvania. Pierce renamed the business the "Pierce Glass Company". The success of the business was so great the company also produced custom bottles for patent medicine competitors including
Pond’s Extract,
Lydia Pinkham and many others.
California gold mining Pierce funded the Big Bend Tunnel and Mining Company, holding "sixty to seventy percent" of the operation's $20,000,000 () capital stock.
Thomas Edison had suggested the gravel bed of the
North Fork Feather River in Butte County, California should be explored for gold deposits. The project required building a dam which formed a two mile lake behind it. The dam diverted the river's water into a large tunnel in order to expose rich gold deposits thought to be in the river's gravel bed. The exposed river bed measured almost a mile in length. Pierce underwrote the Big Bend Tunnel project for $750,000 (). The project started in 1892 and the 12,000 foot tunnel was completed in 1887. The project also required the construction of an electric generation station which provided power for mining equipment and pumps. The construction site was the first to use night illumination which was provided by Edison. Gold was not recovered in amounts to make the project profitable. Although the project was successfully completed, the reported net loss was $2,000,000 (). Pierce said "... after all our efforts and much as we regret to acknowledge the fact, yet we are quite prepared to admit that at present we see no prospect of realizing our former expectations with respect to these mines".
Automobile manufacturer Pierce incorporated his automobile business in 1900 as the "Dr. Pierce Auto Manufacturing Company" in Newark, New Jersey. He began manufacturing, first producing the Pierce electric wagon in 1900, designed for delivering newspapers. That vehicle had a load capacity of 1,000 pounds, used two 10 horsepower electric motors governed to three forward speeds (3, 4 1/2 and 10 mph) and had a range of 25 miles. The car was built in Buffalo, New York. His automobiles had no connection with the
Pierce-Arrow line of autos also built in Buffalo by George Norman Pierce. In 1901 Pierce moved production to Bound Brook, New Jersey. He was able to source the electric motors for his vehicles from his nearby American Engine Company. He expanded the range of electric vehicles to include light delivery trucks and a number of open-top "phaeton" auto models. Pierce said of his automobiles "Our vehicles are built as attractively as is possible without a sacrifice of strength to beauty, which would be dangerous to the stability of the vehicle or perilous to the life of its occupants... Our automobiles have not any of the sulky or spider effect, but are good, staunch-looking vehicles, ready for any test or ordeal". A 1904 Pierce phaeton cost $1,600 (). Pierce reorganized, renaming the automobile company the "Pierce Electric Company". The company was dissolved in 1904. ==Saint Vincent Island game preserve==