Founding and History
For
Orthodox Jews, Judaism was 'founded' by Abraham - the first man on Earth to
adhere to monotheism - and the history of the Jews (up to the end of Biblical
times) is to be found in the Tanakh.
For Reform Jews, Abraham is a often seen as an allegorical figure and the belief is that monotheism developed gradually, as did Judaism. Archaeological, paleological, linguistic and other physical evidence point to the Torah not giving an accurate picture of events and many of the events described in the Tanakh are seen as mythical. The history of the Jews for a Reform Jew, then, is more likely to be in line with current academic thinking.