1000 Saul, David, Solomon---- United Kingdom
=========
930 Rehoboam of Judah (Yah-udah)
--------Divided Kingdom; Divergence of Stories
Jeroboam of Israel (Ysra-el)
==========
722 Deportation of Israel
--------Babylonian Exile; Convergence of Stories
586 Deportation of Judah

There are two separate creation stories:
Gen 1:1-2:3 is distinguished by G-d being called elohim - "gods" - a plurality used as a singular entity (Gen 1:1). The concept of the "council of the Elohim" can be understood best from Job 1.

Gen 2:4 and following is distinguished by G-d being called Yahweh - "I am" - with Elohim (Gen 2:4b). Most English translations substitute the title LORD for Yahweh in deference to the Jewish custom of not reading or speaking the "divine name."

Today we understand both terms to be applicable to the same deity, though this G-d may have had different names depending on whether G-d was worshiped in Judah of Israel. I speculate that Judah (Yah-udah) worshiped Yahweh and Israel (Ysra-el) worship G-d as El or Elohim.

The convergence of the stories happened when the Pentateuch (first five books) was put together from written fragments, memories, insertions, and oral history in Babylon. Scribes from both Israeli and Judean religious traditions were once more united in the task of codifying the history of greater Israel. Therefore, both stories were inserted side by side.

Throughout the Pentateuch, strands of Yahwist and Elohist stories can be detected. Sometimes their are stories from one or the other; sometimes the stories are combined (like the Noah's Ark story).

The Pentateuch is inspired by Yahweh Elohim and worthy of our study and trust. He has preserved it through endless ages in a form that is little changed since the final redaction in the 6th century, B.C. (This has been proven to a great degree with the discovery of all the biblical books among the Dead Sea Scrolls, which date to as early as 4th century, B.C.)