The content of passengers lists, like the US census, varied over time. Very little information was collected in early years. The lists then expanded during peak immigration periods and then shrank again after the peak when immigration procedures changed. Passenger lists were created at the ticket office at the point of departure (or were copies of these original lists). If someone who purchased a ticket didn't make the journey, they will still appear on the list with a line through their name. These manifests can still be useful depending on where the line cuts through the writing.
Following is an excerpt from Rediscovering Passenger Lists.
The 1819 law required that only six items be recorded: 1) name of the passenger, 2) age, 3) gender, 4) occupation, 5) nationality (country of allegiance), and 6) the intended country of destination. Some lists include detailed information about the passengers, such as their baggage or even if a passenger died during the voyage. However, the law did not require, and the lists did not record, the town from which the immigrants left. This is often a great disappointment to researchers who eventually locate their immigrant relatives in the earlier lists.
While the federal government passed laws dealing with immigration in 1819, 1847, 1848, and 1855, these laws had little effect on the keeping of passenger lists other than to mandate that they be kept. When the Supreme Court decided in 1876 that states could not tax or regulate immigration (since issues of foreign commerce are reserved to the federal government), interest in federal legislation grew. Immigration and passenger acts in 1882 provided the foundation for the later more detailed lists. Indeed, even the 1882 Passenger Act called for lists to include native country and intended local destination (such as the state) in addition to the names, ages, genders, and occupations of passengers. Previous lists had only recorded the country of allegiance, which is not always the native country.
The 1891 law required the lists to report last residence of each alien. Two years later, another act that was designed to improve enforcement of the existing law required more than twice as much information on the passenger lists. Hence, the number of columns on the ships’ manifests had increased from five or six columns on the older lists to twenty-one columns in 1893. For the first time, laws required significant information about the passengers and proscribed the nature of the lists, including the limit of thirty names per page. In addition, passenger arrival lists were to indicate marital status; last residence (supposed to have been added in 1891, but not always done); previous U.S. residence, if any; if joining a relative, that person’s name, address, and relationship; amount of money (thirty dollars was required); condition of health; and social detriments, including history of prison, poorhouse, insanity, and polygamy.
A 1903 law made minor modifications, including the race of each immigrant, but it was the 1906 Naturalization Act with 1907 amendments that required a physical description of the immigrant. The law required place of birth (country and city or town), height in feet and inches, complexion, color of hair and eyes, marks of identification, and name and address of nearest relative in the country from which the alien came. (Note: around this time, ship manifests were 2 pages wide so make sure you print/save both pages)