• Early aviation matured through airmail: beginning in 1918, the US Postal Service pushed risky, instrument-free flights that proved air travel’s reliability before passenger aviation took hold.
• The 1925 Kelly Act enabled private carriers like Varney Air Service—later United Airlines—to grow by focusing first on moving mail dependably, making postal service foundational to United’s history.
• Today, United Cargo continues that legacy at global scale, carrying hundreds of millions of kilograms of mail with advanced technology, while preserving the same core promise: delivering meaningful connections people depend on.

In the early 1900s, before commercial flight was a reality, pilots navigated open air without instruments, maps, or guarantees of where they would land. The sky was a test—but it wasn’t people who first proved it. It was mail.

In 1918, the US Postal Service began carrying airmail, taking on the risk of early flight to connect a nation. Small planes threaded through fog, followed railroad tracks, and sometimes landed in open fields when weather closed in. Mailbags strapped into cockpits forced aviation to grow up.

“One of United’s earliest flights carried US mail,” said Stephanie Giraldi, Senior Manager of Postal Network Optimisation and Performance at United Cargo. “That partnership with the Postal Service isn’t just part of our history. It’s the foundation of it.”

By 1925, the Kelly Act allowed private companies to carry mail. One early contract went west to a modest operator: Varney Air Service. Its mission wasn’t to build an airline—it was to move mail reliably. That small operation would grow into what we know today as United Airlines.

“People think of United as a passenger airline,” said Kelly Feeney, Manager of Domestic and AMOT Postal Sales and Operations. “But there’s a whole world moving underneath those flights that most people never see.”

A century later, United Cargo still carries mail, now on a scale early pilots could hardly imagine. Routes span continents. Letters, care packages, and essential shipments travel under passenger cabins, scanned and tracked digitally. From 2020 through mid-2025, United Cargo carried more than 340 million kilograms of mail, generating nearly $1 billion in postal revenue.

“The technology would absolutely amaze those early pilots,” Giraldi said. “But the responsibility would feel familiar. You’re still being trusted with something that matters.”

The human impact endures. For military service members stationed overseas, a care package or letter remains a vital connection to home.

“Mail is often the strongest physical connection to home,” said Kate Hurley, International Postal Operations and Sales Manager. “What began with small planes flying short routes now spans hemispheres. The purpose is still the same: you’re moving something people are waiting for.”

From open cockpits to widebody aircraft, the vehicles have changed. The scale has grown. The technology has evolved. But the promise made on those first flights remains: what’s sent will arrive. Wars, economic shifts, pandemics, and technological revolutions have passed, but mail keeps moving, quietly and consistently, beneath the wings.

As United Airlines enters its second century, the story of mail is a reminder of why aviation exists in the first place. The sky was once a testing ground. It became a pathway. And what began as mail became a century of connection, still unfolding every day.

“We take mail very seriously at United,” Giraldi added. “This isn’t something we treat as an afterthought. It’s about performance. It’s about doing it right, every time.”