Which law increased immigration quotas and eased most remaining restrictions?

The Immigration Act of 1990.

Explanation:

The Immigration Act of 1990 increased immigration quotas to 700,000 immigrants per year. Before it was 657 thousand. It also allowed a family-based visa and created new employment visas that were categorized by occupation.

Another lottery visa was created to low admittance countries and countries that had low representation in the US.

the qing dynasty placed strict limits on foreign merchants' ability to trade in china.

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.