I've been fortunate to find a little more information concerning the ships on which my father's family arrived in the United States in the decade preceding the American Civil War.
Mystic Seaport is a town in Connecticut with a maritime museum that has a great website. If you know the name of the ship and a good approximation of the year it arrived, go to Mystic Seaport. The site has online access to the New York Marine Register for 1857 and to its successor, the American Lloyd's Register of American and Foreign Shipping.
Up until 1857, passengers took their chances getting on board a ship. There was really no reliable way for emigrants to know if the vessel on which they had booked their passage was really seaworthy. Once they'd sold all of their possessions and traveled halfway or more across Europe to get to a major port like London or Hamburg, it was a little late at that point to arrive at the dock and decide that getting on board might not be such a great idea.
The New York Marine Register of 1857 eased that dilemma substantially. It was a publication financed by a number of underwriters who insured the ships on which cargo and passengers traveled. A listing on the register gave passengers a much better idea of what to expect when they arrived at the dock. All of the ships listed on the register were given a rating, ranging from A1+ to A3-. The rating indicated the quality of the construction of the ship and the adequacy of its equipment. Lloyd's of London adopted the system set up for the New York Marine Register of 1857 and within two years the annual publication was known as the American Lloyd's Register.
My great grandfather came to America as an infant with his parents and a two year old brother. They crossed from Hamburg to New York in 1856 on a ship called the Ann Washburn, departing on May 25th and arriving on July 12th after 46 days at sea. The ship was inspected and rated for the New York Register in August that year, presumably while it was still in port following that arrival. Its rating was A1 and 1/2-. The ship was listed at 861 tons and it had two decks. It was built in 1853 at Freeport, Maine, and owned in Boston by H. H. Stevens. It was a new ship, built of oak with copper plating and iron fittings.
My great grandfather's grandparents and their family arrived in New York a year earlier in 1855 on a ship called the London. Its rating or class was 2. The captain's name was Hubbard. The ship displaced 1,143 tons and it had 3 decks. It was built in 1847 in New York by someone named Webb and it was owned in New York by M. H. Grinnell, at that time one of the most prominent shipowners in New York. He is remembered for financing polar expeditions and public lectures by Abolitionist ministers. The London was listed on the American Lloyd's Registry up until 1870, but aside from the 1855 voyage on which my ancestors sailed there isn't much news about it posted online.
The Ann Washburn, however, appeared several times in a column called Marine Intelligence in the New York Times and also in the Times Picayune. The voyage on which my great grandfather arrived from Hamburg in 1856 was notable because a seaman named George Hickson fell overboard and drowned near Nova Scotia. An earlier voyage from Antwerp to New York in April,1854, became controversial because the ship carried Belgian paupers and convicts among its passengers. The ship's captain apparently adopted a policy of excluding such passengers in subsequent voyages.
The ship made the news again in 1858 when it was moored in New Orleans. A tornado touched down along the wharf during a hurricane, wreaking havoc among the ships tied there. Several seamen were flung overboard and the Ann Washburn snapped her bowsprit and sprung a mast. The damage may have not ever been fully repaired. The ship appears to have managed the return voyage to Boston, but a voyage from Boston to New Orleans in November later that year ended in shipwreck at Looe Key near Key West. A fee of $5,000 was paid to a salvage company, probably to recover some portion of the ship's cargo. After 1859 the Ann Washburn was no longer listed on the American Lloyd's Registry.