Harry Joseph Baldwin (1923-2010), the son of Kelsie James Baldwin and Nellie Smith Baldwin, was born in the West End neighborhood of Atlanta, Georgia. He graduated from Technological High School in Atlanta in 1943. He served as an Aviation Cadet in the Navy, Patrol Service Unit 1-3, from 1943-1946. In 1949, Baldwin graduated from the University of Georgia with a Bachelor of Landscape Architecture, studying under Hubert Bond Owens, dean of the Univeristy of Georgia School of Landscape Architecture (now the School of Environmental Design). He was employed by Martini and Associates, Atlanta, Georgia (1949-1952); Lyles, Bissett, Carlisle & Wolfe, Columbia, South Carolina (1952-1955); and Bartholomew & Associates, Atlanta, Georgia (1955-1957). In 1957, Baldwin became an associate partner in Martini and Associates. He assumed ownership of the firm upon the death of Eugene R. Martini in 1965. In August 1967 the name was changed to Baldwin and Associates.

Baldwin practiced landscape architecture until 2005. He is one of the most significant post-World War II landscape architects in the Southeast. Baldwin is recognized as having a keen three-dimensional eye harmonizing with the natural topography in developing his landscape designs. He has been referred to as the "grandfather of landscape architecture" in the metropolitan Atlanta area by other practitioners, mentoring many landscape architects during his long practice. During his six-decade career Baldwin's work encompassed marina, government, institutional, commerical and residential land development projects in Atlanta and the Southeast. Some of his notable projects include Killearn Estates (a 7,500-acre Florida land development project), Dekalb County parks (a large-scale expansion as a result of bond referendum), Morehouse Medical School, West Georgia College master plan, Salvation Army Territorial Headquarters, Rankin Smith Jr. residence, Prince Faisal M. Saud Al Kabir residence, Bald Ridge Marina, Shepherd Spinal Center, Fort Stewart Battalion Headquarters, Falcon Football Team Training Center, Georgia Pacific Tower Plaza, and Martin Luther King Jr. Village.

Baldwin was a fellow of the American Society of Landscape Architects, former president and trustee of the Georgia Chapter of the American Society of Landscape Architects, and distinguished alumni from the University of Georgia. He was also a visiting lecturer at both the University of Georgia School of Environmental Design and Georgia Institute of Technology Extension Service-Site Planning. He was a member of the Atlanta Civic Design Commission (now the Atlanta Urban Design Commission).