Reform Judaism started in Germany, but developed primarily in the United States. The underlying motivation was that Judaism has changed over time in response to variety of factors including a changing world. The religion practiced by Abraham, Solomon or Deborah is not the same as any branch of Judaism today.
Reform Jews generally believe that after learning about the religious texts and their historical interpretation into religious laws that the application of those laws may be adjusted to fit the current world. For example, the laws that govern the ethical treatment of your horse may not apply to your car.
- Union of Reform Judaism -- the parent organization of reform congregations