What year was the American frontier considered officially closed?

Answer 1

The period of intra-colonial constitutional activity that marked the closing of the first generation also marked the opening of the second. It was followed by a period of generational buildup that saw the introduction of further federal experiments on the regional plane leading to the United Colonies of New England which functioned on and off during the generation plus further efforts to shape the internal structure of the individual colonies themselves.

Answer 2

The "wild west" era began to fade during the mid/late 1890's into the 20th Century.

While this is somewhat true, what defining qualities you're attributing to the era that make it unique effect the start and end dates of the era. The West was never quite as wild as is commonly thought, and law enforcement and social contract were almost always in place from the outset of settlement. Taking into consideration the expected imagery, it can be said that the era began as early as 1830 (some would argue for earlier) and was pretty well transitioned by 1920. Over this span of time there would have been a slow, trickling, stream of minor changes that altered life in the west. It takes a lot of research and study to fully understand just how non-linear history and this particular era were.

The short answer would be that the era lasted roughly from 1830-1920.

Answer 3

It was considered officially closed in 1890 because the census of 1890 stated so.

Answer 4

The American Frontier officially ended in 1955 because the Census of 1955 wanted it to end.