Donegal Insurance Group sells Donegal auto insurance in 20 state markets and is one of the oldest and most well established insurance providers in Pennsylvania. The company expanded from its Pennsylvania roots through a series of strategic acquisitions that started in the 90s, but it remains one of the lesser known mid-sized insurance companies even though it has increased its annual premiums substantially in recent years. The company is known for its strong financial stability and for having a stable financial outlook, and it may be a good choice for customers who happen to be looking for insurance in one of its 20 states.