What does abbott's recollection tell you about the changing frontier?

When Europeans arrived in America in the 1600s, the frontiers began moving west. As they continued spreading their land occupation, American Indians were moved west. In 1889, the  government transferred white  colonists the Indian land, breaking the promise, as these lands had been promised to Indians. The Indians tried to take over those lands to no avail. In 1890 the Bureau of the  Census stated there were no frontiers within the  country.

ford’s revolution of the assembly like to make cars less expensive

explanation:

the confederate at bull run