Yes you can. The Cunard cruise line offers regular service between New York and Southampton, England via the Queen Mary 2 and occasionally with their other ships the Queen Elizabeth and the Queen Victoria. Check the Cunard website for a schedule of sailings. There are transfer services available to get you to London from Southampton.
Yes, US citizens need a visa to travel to London.
By Boat
Yes, a US citizen does not need a visa to travel to London for stays up to 6 months.
It depends on where in the US you are going to.
no you must drive a car
Yes you can if you take a boat or a plane
it would cost you $5287 to go from the US to London on a ship.
Yes, mostly during the Gilded Age during 1890-1903.
Mostly north.
It depends where you live.
It is about 5000 miles from Germany to US. There were no airplanes back then so obviously, the only way to travel would be by boat. In mid 1800s the average speed of a boat was 20 mph. Thus it would take about 250 hours or about 12 days, considering slowing down in the night.
Preferably by sea. However, travel to Cuba from the US is not allowed.