Though congress passed legislation to restrict immigration in the early 1920s, one border was left relatively open. which border was this, and why? the canadian border was left open because canada and the united states had recently signed a treaty to restore peace in the north american region. the east coast was left open because of business agreements with eastern european countries, which brought money to the united states. the mexican border was left open because labor coming from mexico was particularly cheap, and many agricultural workers were needed. the west coast was left open because asian immigrants had recently been allowed to enter the united states following a long period of exclusion.

The Navigation Acts were a series of laws that restricted the use of foreign ships for trade between every country except England. This ended 200 years later. They reflected the policy of mercantilism, which sought to keep all the benefits of trade inside the Empire, and minimize the loss of gold and silver to foreigners. They prohibited the colonies from trading directly with the Netherlands, Spain, France, and their colonies. The original ordinance of 1651 was renewed at the Restoration by Acts of 1660, 1663, 1670, and 1673 subsequently subject to minor amendment. These Acts formed the basis for English overseas trade for nearly 200 years. Another way to define this is laws created by England to limit their colonies' trade with other countries. Additionally the Navigation Act restricted the employment of non-English sailors to a quarter of the crew on returning East India Company ships.