Lewis then embarked on what would become an incredibly successful business career, building wealth and stature in several arenas, but perhaps most so in the fields of automotive sales, television broadcasting, and real estate.

Lewis started his life by inheriting Georgia's oldest Ford dealership from his father and built a diversified family empire.

He "proved to be a brilliant businessman, opening additional Ford dealerships in Daytona Beach and Melbourne, Fla., adding new brands to his Savannah dealership, and investing in tractor sales, taxi cab businesses, television and radio stations, hotels, life insurance, yacht sales and real estate."

Lewis was instrumental in developing the southside of Savannah,[1] along Abercorn Street and an adjacent area of the city presently known as Habersham Woods.

[3] Although he did not exploit the racial issues, he benefited from a backlash from white voters against the popular Democratic incumbent, Malcolm Maclean.

[6] In the early 1960s, Lewis, a former YMCA president, donated 8.5 acres (3.4 ha) of land on South Habersham Street and went on to lead the 1964 capital funds campaign.

While serving as Mayor in 1967, he was approached by then Sheriff Wilkes S. MacFeeley about establishing and operating a "One Hundred Club"[8] to provide financial support to the families of law enforcement officers and firefighters killed in the line of duty.

He had remained active in the community, serving as a director on numerous civic and business boards throughout the southeast up until his death.

He was an avid yachtsman, amateur radio operator (FCC EXTRA Class), family man, and Sunday School teacher (church deacon).

[6] Lewis was the primary benefactor and sustained numerous organizations and various charitable groups over the years throughout the southeast with a focus on the Savannah area donating untold sums in the multiple millions in cash to numerous organizations (many times unknown to the public) including over $5 million to the Union Mission (August 23, 2005 Savannah Morning News), which provides shelter for men, women, and families, short- and long-term housing assistance, health and dental care, behavioral counseling, substance abuse programs, life skills training, job training and employment assistance to the low-income population of the Coastal Empire, and to the First Baptist Church of Savannah on Chippewa Square, where Lewis was a member for 66 years.

Lewis also donated the land for numerous other nonprofit groups throughout the Savannah area including the Congregation Agudath Achim[9] and the B'nai B'rith Jacob Synagogue's apartment complex, The Episcopal Church of Oakdale, Georgia, The Skidaway Island Community Center, Virginia Heard Public School, New Hope African Baptist Church of Savannah, The Word of God building & (Alzheimer's Association Coastal Georgia Region), and a portion of the land for The Savannah Jewish Educational Alliance (JEA) as well as a portion of the land for the Jepson Center for the Arts of the Telfair Museum of the Arts in downtown Savannah which houses the J.C. and Nancy Lewis Gallery on its top floor featuring rotating exhibits throughout the year.

In 2005, the 62,000 sq ft freestanding cancer treatment & research center of St. Joseph's/Candler Hospital was renamed to honor Lewis.

[12] In 2003, S. 1671, a White House Archives bill was passed to designate the facility of the United States Postal Serviceat 10701 Abercorn Street in Savannah as the "J. C. Lewis Jr. Post Office Building".