He studied medicine at Albany Medical College where, in 1840, he graduated cum laude and briefly served as assistant professor of surgery.

While working with the prairie wheat trade, Durant realized the need for improved inland transportation, which led to his interest in the railroad industry.

As general agent for the UP Eastern Division, Durant was also charged with raising money, acquiring resources, and securing favorable national legislation for the company.

In addition to securing an enlarged land grant from Congress in 1864 as part of the legislature's subsidizing distribution of 100 million public acres, Durant effectively reacted to the Union Pacific's failure to sell significant stock in light of the Pacific Railway Act of 1862 ruling that merchant holding would be limited to 200 shares per person.

Proposing to finance the required ten percent down payment on stock himself, Durant campaigned to brokers and merchants in the New York and Philadelphia areas on the condition that he would be reimbursed at a later date.

During the Civil War, Durant made a fortune smuggling contraband cotton from the Confederate States with the help of General Grenville M.

Durant and entrepreneur George Francis Train joined in March 1864 to form a business venture to buy out the Pennsylvania Fiscal Agency, changing its name to Crédit Mobilier.

Durant created this limited liability company to encourage UP investors to agree to take on the railroad's construction after contracted employee Herbert Hoxie announced that he would fail to meet his deadline for building 247 miles of track.

Ames had been a member of the United States House of Representatives from Massachusetts and assisted Durant in bribing congressmen and other government officials.

In 1873 Durant summoned his family home to rebuild their fortune in the Adirondack Wilderness, where he had accumulated a half a million acres of land.

At the time, he owned the Adirondack Railroad and was seeking investors to continue the track from North Creek, NY on into Canada.

William's camps Pine Knot, Uncas and Sagamore were eventually sold to Collis P. Huntington, J.P. Morgan and Alfred Vanderbilt.

Héloïse attended private schools in Europe and the United States, and was fluent in Arabic, French, German, and Italian.

She became an American author, playwright, and book reviewer for The New York Times, and she wrote in addition to articles and plays essays, poems, and short stories.

(Other prominent signers included Susan B. Anthony, Caroline Sterling Choate, Chauncey M. Depew, Parke Godwin, Emma Lazarus, Josephine Shaw Lowell, Theodore Roosevelt, Georgina Schuyler, and Charles Comfort Tiffany.)