Why was John Ross confident the Cherokee would stay in Georgia, even after the Indian Removal Act was passed in 1830?

His faith in the US Government

Explanation:

John Ross was the principal chief of the Cherokee and ruled till he died. He was a biracial man and a great diplomat who used both his skill and racial identity to fight for the rights of the Cherokee.

Georgia wanted the lands that the Cherokee stayed in on Georgian territory for multiple reasons chief amongst them being that Indian territory had gold. They therefore passed laws to remove the Indians from their territory and Congress supported them with the Indian Removal Act.

John Ross did not despair completely however because he believed that the United States government and its institutions such as the Supreme Court and Congress (where they had support among the Whig party) would protect the rights of the Cherokee as he kept mounting legal challenges against attempts to remove them.

Eventually he realized that the US government would not protect them and after the fraudulent Treaty of New Echota was given the assent of the US Senate, he switched gears to negotiating the terms of the removal process.