He worked as staff administrator and treasurer of a non-partisan commission studying the selection process of U.S. presidential nominees.

Roosevelt was mentioned, by name, in an essay on Time Magazine's 1967 Man of the Year in which he responded to the question of why he was involved as a VISTA volunteer in Harlem, New York with a single word, "individualism".

[16] From 1983 to 1987 Roosevelt was vice president at Gray-Judson & Howard, Inc, a management consulting firm which provides strategic planning advice to domestic and international clients in both the industrial and service sectors.

Projects that Roosevelt directed or participated in included: developing and implementing strategic planning processes for a number of regional brokerage firms; developing a strategic financial profit model for a major law firm; analyzing the market planning system for an international health and fitness service organization; and consulting with other clients including Computervision (a manufacturer of CAS/CAM systems), J. T. Lupton (the largest Coca-Cola franchise bottler in the U.S.), Allied Signal Corporation, Kodak, Mutual Life of Canada, and Cardio Fitness Corporation.

He also provided investment banking services to small companies, arranging both short-term and long-term financing.

Roosevelt has also served as spokesperson for Steiff, an international company headquartered in Giengen, Germany, that manufactures extremely high quality collectible plush animals, including Teddy Bears.

At the beginning of the 20th century, Steiff was the initiator of the original Teddy Bear, which was named after President Theodore Roosevelt.

The firm was primarily known for a failed venture to bring Saks Fifth Avenue retail stores to China.

He leads them in discussions of various documentaries, literary texts, and also provides tours through Theodore Roosevelt's home in Sagamore Hill, which he grew up in as a child.

He presented two seminars during Safari Club International (SCI)’s 2005 Convention: Return for the River of Doubt and Theodore Roosevelt Remembered.

Tweed's great-uncle, Theodore Roosevelt Jr., served as Governor of Puerto Rico in the early 20th century.

[24] On June 8, 1980, Roosevelt married Candace C. MacGuigan, at Brick Presbyterian Church in New York City.