Expedia started as a project inside Microsoft. Rich Barton, a young Microsoft manager, argued that travel agents' booking systems belonged on the web, where anyone could search fares themselves. Microsoft launched Expedia in October 1996 and soon had sites in Canada, Britain and Germany. In November 1999 Microsoft split the business out and sold a slice to the public. Online travel was one of the few web businesses with real revenue, and Expedia was one of its biggest names.

A Startup Inside Redmond

Barton ran Expedia as a small business unit inside Microsoft. Expedia let people compare flights, book hotels and rent cars from one page, around the clock. It earned commissions and fees on each booking. Microsoft's money and its MSN portal brought traffic that a small startup could not buy. By the time of the offering, Expedia had sites in four countries, and Microsoft still held most of the company.

Diller Takes the Wheel

Expedia priced its IPO at $14 a share in November 1999 on Nasdaq. Two years later Barry Diller's USA Networks bought control from Microsoft, and by 2003 it owned the whole company. In 2005 Diller spun Expedia back out as its own public company. It grew into Expedia Group, owner of Hotels.com and Vrbo. Barton went on to found Zillow. Expedia Group still trades on Nasdaq under EXPE.

Cover: Mountain transportation. Pack mule, Pack and Packers, No. 7, Timothy O'Sullivan. Art Institute of Chicago, public domain. Chosen for a pack-mule expedition (Expedia).