Final answer:
Jacob's first son with Rachel is Joseph.
Step-by-step explanation:
According to the Hebrew Bible, the first patriarch (male clan leader) of the Hebrews was Abraham. Abraham had a son, Isaac, and Isaac had a son, Jacob.
The name of Jacob's first son with Rachel is Joseph.
Joseph played a significant role in biblical history, as he was sold into slavery by his brothers and eventually became a powerful ruler in Egypt.