Three years after her husband's death, his mother moved her six children from Brooklyn to Mahwah, New Jersey to be near relatives.

[3]: 1  The young Birches quickly became friends with the children of their neighbors, Theodore Havemeyer, the vice-president of American Sugar Refining Company, and his wife Lillie.

[4] At the prime of the Klondike gold rush in 1898, Birch decided to go to Alaska rather than continue working with an engineering team that was surveying for the New York City subway system.

[3]: 3  Mrs. Havemeyer offered to pay for his trip to Valdez, a newly established city named the port for an All-American route to Alaska's interior.

As resources were depleted at the Alaska Mines, which closed in 1938, Birch led the diversification into related products and alternate sources of copper in Utah, Nevada, Arizona, New Mexico, and Chile.

[3]: 75 Kennecott Copper Company's original location in Alaska is now frequently referred to as a "ghost town" and is a tourist attraction.

The buildings and mills are still standing but remain untouched, as the company's Alaska location closed down many years ago.

During his lifetime, he avoided publicity and seldom gave interviews or had his picture taken, though he did have his portrait painted in 1911 by Swiss-born American artist Adolfo Müller-Ury.

Today one of the financial powers in New York City, he shuns publicity and evades acclaim as a captain of industry.

"[3]: 77–78 In 1938 he founded the Stephen and Mary Birch Foundation, Inc. to support health services, hospitals, and civic organizations.

It provided major funding for the Stephen Birch Aquarium-Museum at the University of California, San Diego.