How we cite our quotes: (Section)
Quote #1
That the master of any vessel who shall knowingly bring within the United States on such vessel, and land or permit to be landed, any Chinese laborer, from any foreign port or place, shall be deemed guilty of a misdemeanor. (Sec.2)
You could easily look at the Chinese Exclusion Act as not just a law against a minority, but a law designed to keep them a minority. While the term in the United States often gets interpreted to mean "non-white," leading to people occasionally using paradoxes like "majority minority" with a straight face, minority really means just that. Less than the majority. The Chinese Exclusion Act aims to keep the population of Chinese laborers small, and that way, they stay minorities.
Quote #2
[…] every such Chinese laborer so departing from the United States shall be entitled to, and shall receive, free of any charge or cost upon application therefor, from the collector or his deputy, at the time such list is taken, a certificate, signed by the collector or his deputy and attested by his seal of office, in such form as the Secretary of the Treasury shall prescribe, which certificate shall contain a statement of the name, age, occupation, last place of residence, persona description, and facts of identification of the Chinese laborer to whom the certificate is issued. (Sec.4)
The very fact that they want to keep this much information on the Chinese tells you that there couldn't be that many of them. Remember, this was before computers. All of this stuff would have been tracked by hand in giant books. This isn't something you can do to a bustling, vibrant population.
Quote #3
That any Chinese laborer mentioned in section four of this act being in the United States, and desiring to depart from the United States by land. (Sec.5)
The law takes sea as the default way for Chinese people to get in and out of the U.S.A, and this makes a lot of sense. However, this also assumes there's not much of a Chinese immigrant population in either Canada or Mexico. There is now, but at the time, people of Chinese descent were tiny immigrant groups.