WASHINGTON • When the robots came to online retailer Boxed, dread came too: The familiar fear that the machines would take over, leaving a trail of unemployed humans in their wake.

“I had a lot of people asking me, ‘What is going to happen to us?’” says Veronica Mena, a trainer for the e-commerce startup. Anxiety had rippled through her co-workers after company executives announced plans to open an automated warehouse in nearby Union, N.J.

Yet their fears didn’t come to pass.

When the new warehouse opened this spring, workers found that their jobs were less physically demanding than at the previous, manual warehouse in Edison, N.J. And rather than cutting jobs, the company added a third shift to keep up with rapidly growing demand.

What happened at Boxed — and has occurred elsewhere — suggests that widespread fears about automation and job loss are often misplaced. Automation has actually helped create jobs in e-commerce, rather than eliminate them. By accelerating delivery times, robotics and software have made online shopping an increasingly viable alternative to brick-and-mortar stores, and sales have ballooned at online retailers.