Hartsfield-Jackson International ranks second in the nation for domestic connections, according to an annual report on megahubs by aviation intelligence firm OAG.
Chicago O’Hare ranked first with more connections between domestic flights in the United States, as a hub more centrally located for such connectivity.
Hartsfield-Jackson is the world's busiest airport based on passenger counts, but O'Hare is the world's busiest based on flight counts.
The ranking is based on a comparison of the number of scheduled connections with the number of destinations served.
Delta uses its Atlanta hub as a connecting point to and from places around the Southeast and for international connections to Europe, Latin America and other regions. It has smaller hubs in cities such as Minneapolis/St. Paul and Salt Lake City for other passengers connecting across the country.
According to the report, there are 63,466 possible connections passengers could make at Hartsfield-Jackson on the busiest day in 2019, with Delta operating 79 percent of flights.
Southwest Airlines, the second-largest carrier in Atlanta, focuses more on travelers going to and from Atlanta and less on connections than a traditional hub carrier might.
Globally, O'Hare ranked third for international connectivity and Hartsfield-Jackson ranked 8th. In the top position for international connectivity was London Heathrow, followed by Frankfurt.