Dear Ms. Schreuders,
Thank you for posting your request on History Hub!
Until January 1, 1820, the U.S. Federal Government did not require captains or masters of vessels to present a passenger list to U.S. officials. Thus, as a general rule, NARA does not have passenger lists of vessels arriving before January 1, 1820. There are, however, two exceptions to this general rule: Passenger Lists of Vessels Arriving at New Orleans, Louisiana, 1813-1849 (M2009) and Passenger Lists of Vessels Arriving at Philadelphia, Pennsylvania, 1800-1882 (M425 & M360). For more information, please see NARA’s Immigration Records web page.
The departure from the U.S. to Australia likely is not recorded formally anywhere in U.S. Federal records, but it is possible to find their arrival in Australia. For records in Australia, we suggest you contact the National Archives of Australia for immigration and citizenship and the
National Library of Australia for shipping and passenger records. If they happened to arrive through Victoria, we suggest searching the Victoria Coastal Passenger Lists, 1852-1924 on FamilySearch.
For the return to the US, there should be a recording of their arrival back in the US but without a known port of arrival, you may need to be open minded about possible locations where the family may have reentered (even considering the possibility that the family may have ultimately reentered the US overland, which was not recorded at that time). Again, looking for a record from Australia is a possibility. If they happened to depart through Victoria, we suggest searching the Victoria, Outward Passenger Lists, 1852-1924 on FamilySearch.
We hope this information is helpful. Best of luck with your family research!
[Information provided by Elizabeth Burnes, Subject Matter Expert]