When did the land bridge theory begin? and what did it argue

It began in 1997 with the discovery of an archaeological site in Monte Verde, Chile, dating back to 14,500 years ago - a full millennium older than what was previously thought to be the first people in the new world, and indicating they settled much further south than expected.

because it had logic

Explanation:

christopher columbus (1492–1504)

1. darius the great     persia  

2. piankhi       nubia

3. ezana       aksum

4.     nebuchadnezzar     babylonia

5. shalmaneser iii     assyria