After beginning his career at Kidder, Peabody in 1880 as a lowly clerk just out of college, Winsor was quickly promoted because of his business acumen, and was held in such great esteem by the 1920s that newspaper articles would refer to him as the "J.P. Morgan of Boston" and "one of the country's leading bankers.

Just after his death, a front-page story in the Boston Sunday Post declared Winsor “perhaps the greatest” of a group of same-aged business and political leaders (many of them classmates in the Harvard class of 1880), including Theodore Roosevelt, Josiah Quincy, Richard Saltonstall, Robert Bacon, and William A. Gaston, who had been responsible for building the country's banking, telephone, and transportation industries: “Winsor had the insight that saw the transportation needs of the last four decades.

[4] After graduation, Winsor joined the Boston investment banking firm Kidder, Peabody & Co. as a clerk, but was quickly recognized for his business acumen, earning the highest Christmas bonus in the company in his first year as a result of his success.

By 1895, Winsor on behalf of Kidder, Peabody was able to gain control of both companies, reorganizing them into one unified public transit system of subways and surface and elevated lines serving metropolitan and suburban Boston.

After 1919, Winsor became the leader of Kidder, Peabody's entire operation, and the man principally responsible for cultivating new business, organizing syndicates, and negotiating deals with other investment houses.

But as the consumer-driven society exploded in the post-war years, Kidder, Peabody had trouble keeping up with the expansion, which was partly attributed to Winsor's autocratic leadership and inability or unwillingness to adapt to the changing times.

Another factor in Winsor's downfall and failing health was his very prominent role as a defendant in the 'Willett v. Herrick and others' court case, which dragged on from 1921 through 1927, attracting as much attention in Boston as the simultaneous Sacco and Vanzetti murder trial.

Although it was at its heart a simple civil suit, it involved a great deal of property and the reputations of some of Boston's most esteemed citizens, and like the Sacco/Vanzetti trial raised serious questions about the functioning of the Massachusetts courts.

Most of the firm's capital at that time was tied up in securities of companies it had financed and reorganized, whose value had plummeted so much with the crash that many were completely unsellable, effectively freezing most of Kidder, Peabody's assets.

When Winsor died of a heart attack on January 7, 1930, just three months after the crash, the firm was skating on the edge of bankruptcy and was forced to accept a $10 million bailout from J.P. Morgan to survive.

Individually and collectively the group had enormous financial power, working together in syndicates, floating the securities of the largest American corporations, marketing them through allied trust and insurance companies and banking correspondents throughout the world, or placing them on the New York Stock Exchange.

(The notes of Frederick Law Olmsted Jr. from their meetings states that “He wants to keep the place quiet and natural.”) He also offered some of his land to create a skating/swimming pond and relocate the Meadowbrook School and the Weston Golf Club (designed by Donald Ross), boosting the value of his property immeasurably.

The Weston Real Estate Trust was selective in its sales, keeping lots at two acres or larger (creating the protective zoning followed by the town to this day), and even organizing a competition for architects to design homes to be built on the land.

[5] Before 1911, inspired by the plans of Edward Filene's "Boston-1915" project and others meant to address substandard housing and living conditions among the working class, Robert Winsor suggested the idea of building a "scientific, model residential enclave" for the conductors and motormen of his Boston Elevated Railway "as an alternative to the ills of urban housing and congestion," located "within fifteen minutes of the business center of Boston on a five cent fare."

After studying several garden-based residential communities in London, Birmingham, Liverpool, and Germany, his hope was that such a community would serve as an “object lesson, which will lead others to make similar investments.” On November 30, 1911, Winsor organized the Boston Dwelling House Company to develop a 30-acre site near the Forest Hills terminal “with the object of providing desirable, attractive, and sanitary homes at a moderate cost or rental for persons, desiring the same and for the purpose of acquiring the real estate."