Through his banking activities, he played a significant role in the early years of the Standard Oil company.

[4] Canvass White, an engineer and inventor, frequently rode the ferry, and became impressed with Stillman's attentiveness, attitude, and drive.

Some sources claim that Witt helped to construct the dam and the six power canals, as well as platted the emerging village of Cohoes.

[7][4] Maurice Joblin, however, says he fell ill shortly after arriving in Kentucky, and returned to Albany for 13 months of recuperation.

According to business biographer James W. Campbell, Witt next became an agent[c] for the Hudson River Steamboat Association.

[8][d] Joblin, however, says that Witt first captained the James Farley, a steamboat on the Erie Canal, for an unspecified period of time.

Witt also worked with Amasa Stone, who at that time was active constructing railroad bridges throughout New England.

[43] In November 1848, the company finally issued a request for proposals to build the first leg of its line from Cleveland to Columbus, Ohio.

[41] Kelley and the CC&C managers reached out to Harbach, Stone, and Witt, and asked them to bid on the project.

[4] Witt was elected president of the B&I after Brough died in September 1865, and held that position until the B&I merged with the CCC&I on May 16, 1868.

This steam streetcar line cost $68,000 ($1,556,520 in 2023 dollars) to build, and ran for 3.3 miles (5.3 km) down Willson Avenue (now East 55th Street) and then Kinsman Road to the Village of Newburgh (now the southwest corner of the Union-Miles Park neighborhood).

[4][r] That same year, he was elected a director of the Detroit, Monroe and Toledo Railroad,[115] and was holding that position in 1875 when he died.

[116][s] The national news media called Stillman Witt one of Cleveland's greatest bankers of the post-Civil War period.

That year, he partnered with Hinman Hurlbut, James Mason, Henry Perkins, Joseph Perkins, James Mason, Amasa Stone, Morrison Waite, and Samuel Young to purchase the Toledo Branch of the State Bank of Ohio.

The SIC would also provide the investor-refiners with information on the shipments of their competitors, giving them a critical advantage in pricing and sales.

[135] Rockefeller saw the SIC as the ideal mechanism for achieving another goal: A monopoly on oil refining in Cleveland.

The monopoly would allow Standard Oil to dominate the national refining market, garner significantly higher profits, and drive even more competitors out of business.

To secure the cash, Rockefeller allowed Amasa Stone, Stillman Witt, Benjamin Brewster, and Truman P. Handy[v]—all of whom were officers in Cleveland banks—to buy shares in Standard Oil at par in December 1871.

[138][w] Witt and the other bankers used their influence at their own and other banks to give Rockefeller the financial backing he needed.

Rockefeller knew that if he bought out the weak refiners first, he'd generate opposition and never get a chance to take on the larger, more profitable ones.

Payne swiftly agreed to a merger of his interests with Rockefeller's, and the transaction closed in early January 1872.

With the company's insurer refusing to pay until after an investigation, Standard Oil was in desperate need for cash to rebuild.

At a meeting between Rockefeller and the bank's directors, Stone demanded that Standard Oil be appraised and its financial condition assessed before any loan was issued.

He served as a founding member of the Cuyahoga County Military Committee, which formed in 1863 to help recruit volunteers to fight for the Union during the American Civil War.

[175] His service found national expression when he was elected an associate member of the United States Sanitary Commission in 1861.

[180] Witt was also one of the major original investors in Cleveland's Lake View Cemetery when that organization was first founded in 1869.

[183] With the illness still afflicting him, Witt decided to travel to Europe in late spring of 1875 to seek the restoration of his health.

His physical health rapidly declined during that day, and he was attended to by his personal physician and the ship's doctor.

[189] Considered one of the most beautiful homes in Cleveland at the time,[190] the Neoclassical style[191] edifice featured massive Ionic columns in front.

[189] In 1869, Witt purchased for $5,000 ($100,000 in 2023 dollars) a house and lot at 16 Walnut Street,[192] and donated these to the Young Women's Christian Association (YWCA) as a boarding home for single, unwed mothers.