GuideOne Insurance
West Des Moines, IA, USA

The Hanover Insurance Group, Inc., based in Worcester, Massachusetts, is one of the oldest continuous businesses in the United States still operating within its original industry. It was the original name of a property-liability insurance firm born in 1852, and it remained a publicly traded company under that name until the early 1990s, when it changed its name to Allmerica Property & Casualty Companies.