They were slaves because the Pharaoh was afraid they would overpower him, so he forced them to work all of there lives.
Israelites
The Israelites were slaves in Egypt for roughly 400 years .
Before
Pharaoh would not release the Israelites from Egypt. The Israelites were slaves to the Egyptians and God commanded Moses to free them.
they served judges and cannaaanitesz
It told of the Israelites' escape from slavery.
They lived in Israel before they were taken as slaves to Egypt.
A person doesn’t “become” a slave instead they are taken in war as slaves.
Moses was the leader of the Israelites, 3300 years ago. The Bible (the first chapters of Exodus) relates how he brought the Israelites out of the Egyptian slavery at God's command.
The Torah teaches us that Moses traveled with the Israelites through the desert for 40 years. Then the Israelites went on to the land of Israel and he died.
The Egyptians made a final attempt because they were trying to get the Israelites as their slaves again, and he destroyed them so they couldn't follow the Israelites because they were his people.
The Gibeonites were slaves by choice at least when the book of Joshua was written. Joshua 9:27. They were still under Israel's promise by 2 Samuel21:1-14, and had to be avenged. We see them come back out of Israel's Captivity in Nehemiah 7:25, presumably not as slaves any longer, probably having mixed in with the Israelites.