During the Great Depression, the store had become run-down, and it was sold to William B. Ginsberg, an Eastern-European immigrant who came to New York and earned his Doctorate of Pharmacy from Columbia University.

Alec Ginsberg, Ian's son and fourth generation pharmacist, currently serves as the company's Chief Operating Officer after joining full-time in 2016.

[5] He also moved the business two doors north, to a new home at 106–108 Sixth Avenue (today number 414, after the street's renumbering in 1929).

During the extensive blackouts on the East Coast in 1965 and 1977, Bigelow's was the only pharmacy between Maine and the Carolinas with enough light to remain open for business.

Famous patrons of C. O. Bigelow, featured in advertisements, include Thomas Edison, Eleanor Roosevelt, and Mark Twain.