Final answer:
The purpose of the letter was to inform and persuade the Seminole people about the Indian Removal Act. President Jackson referred to the Seminole as 'my children' to assert his authority. He was truthful about his intention to remove Native American groups, but not about the voluntary nature of the removal.
Step-by-step explanation:
The purpose of the letter is to inform the Seminole people about the Indian Removal Act and to persuade them to voluntarily relocate west of the Mississippi River. President Jackson refers to the Seminole as 'my children' as a rhetorical device to create a sense of paternalistic authority and to convey his belief that he knows what is best for them.
President Jackson was telling the truth regarding his intention to remove Native American groups living east of the Mississippi River. He also told the truth about the pressure that was applied to these groups to remove. However, he was not telling the truth when he claimed that removal would be voluntary.
The Seminole experience during Indian removal was similar to that of other Native American groups in that they faced tremendous pressure to relocate and many suffered from exposure, disease, and starvation during the journey. However, the Seminole also put up significant resistance and ultimately, some individuals were able to remain in the Everglades.