How was reform judaism started?

According to Jewish tradition, Abraham was the first Jew. He became the progenitor of the Jewish people when he renounced idolatry and demonstrated belief in one God around the year 1712 BCE

According to Jewish tradition, It started in Israel with Abraham. He became the progenitor of the Jewish people when he renounced idolatry and demonstrated belief in one God around the year 1712 BCE.

Tradition holds that Judaism began with Abraham, about 4000 Years ago.

Judaism can be traced back for thousands of years to the times of the Fertile Crescent. it all started when Abraham was spoken to by god in the ancient Mesopotamian city of Haran he was told to leave...

Not really. Tradition holds that it began with Abraham, who abandoned idol worship (polytheism) to worship the one God.