Check out the $600 million Alabama factory where Airbus builds jets for American, Delta, and JetBlue

Over the last five decades, Airbus has developed into a global aviation giant. The European consortium and Boeing now make up the duopoly that dominates the global commercial aircraft industry.

But most people are not aware of the substantial manufacturing footprint Toulouse, France-based Airbus has in the US. This includes helicopters in Mississippi and satellites in Florida.

And then there's the crown jewel, the commercial aircraft final assembly line in Mobile, Alabama.

This is where the company produces Airbus A320-family jets for US customers such as American, Delta, Jetblue, Frontier, Spirit, Allegiant, and Hawaiian Airlines.

The Airbus A320-family of jets, which includes the A319, A320, and A321, is also assembled in Toulouse, France; Hamburg, Germany; and Tianjin, China.

Read more: The amazing story of how the Airbus A320 became the Boeing 737's greatest rival.

The European aviation giant first made its presence felt in Mobile with the establishment of the Airbus Engineering Center in January 2007 that has since helped develop systems for the Airbus A330, A350, and A380 airliners.

Back then, there were quite a few people within the company that questioned whether a Mobile campus was really needed, Airbus Group CEO Tom Enders recounted to reporters in January. There are "no longer" any doubters, Enders added.

In January, Airbus broke ground on a second final assembly line at its Mobile complex to build the new A220 airliner. The A220, previously known as the Bombardier C Series, is currently assembled exclusively in Mirabel, Quebec, Canada.

Read more: Boeing started a trade dispute with Canada, but Airbus and Alabama ended up being the winners.

The new Mobile A220 plant is expected to produce four planes a month, Airbus Americas CEO Jeff Knittel told reporters.

Shortly, after the groundbreaking ceremony, Business Insider got the chance to step inside the A320 plant.

Here's a closer look at the Airbus A320-family production facility in Mobile, Alabama.