Where will I find the passenger list for someone who emigrated to America?

The basic rule of thumb is that, for the period prior to 1890, expect the passenger list to have gone with the passenger and ended up in the port of arrival. This means that you should not expect to find a passenger list for an outgoing ship in Scotland and you ought to check sources in the United States first.

First you may be lucky enough to find a record of your ancestor in published passenger lists (which account for about 1% of emigrants to North America).

Next try the US National Archives and Records Administration where all surviving passenger lists for vessels arriving in the United States are kept. They are divided into two types of record: Customs Passenger Lists, 1800-1890, which give the name, age, sex, occupation, country of origin and country of destination of each passenger, but do not cover all American ports; and Immigration passenger lists, from 1890, giving all of the above information, along with place of birth, last place of residence and sometimes the address of a relative in the country of origin. <https://www.archives.gov/research/immigration/overview> [accessed 26 April 2024].

The UK National Archives in London holds passenger lists for vessels leaving the UK between 1890 and 1960 (among the records of the Board of Trade). For further details consult the Discovery website. <https://discovery.nationalarchives.gov.uk/> [accessed 26 April 2024].