The ancient people were moving west.
The bridge that you are referring to was called the Bering land bridge which is now the Bering Strait. During the Ice age, though this area was covered in ice which made the sea levels drop and emerged the land bridge, the land bridge was covered with grasses and low shrubs which provided food for the mammoth, horses, caribou, and bison. It is believed that the ancient people followed these grazing animals from beringia (which is now SIberia) and into America, they are believed to be the first inhabitants of America. Over time the weather got warmer and the glaciers started melting and the bridge started disappearing into what we now call the Bering strait this all happened about 11,600 years ago
Nominating conventions related to politics because at nominating conventions political parties seek to decide who they will nominate to run in different elections. Nomination conventions are often times the place where the parties formally announce the nomination of a candidate who has been chosen by a caucus or electoral process either in a state or nationally.
People came for a variety of reasons, including economy, adventure, health, and philosophical notions such as Manifest Destiny. During the early 1830s affluence, Americans gambled heavily on the land, resulting in the Panic of 1837 and the following downturn.
Ultimately, the end of the Vietnam war resulted in communist control of Cambodia,Laos,and Vietnam. The Vietnam war was fought between 1st of November in the year 1955 to 30th of April in the year 1975.