the magical sea lift from Europe
"In the late 19th Century, two steamers were considered to be required to transport a regiment of infantry on a long voyage. For a division of 10,000 men, a least 30 steamers were calculated to be required; for a corps of 33,000 men, 135 steamers. No nation except Great Britain and possibly France possessed enough ships to carry 50,000 troops across an ocean.
In theory, Great Britain might have transported 500,000 men; but that would have required all her shipping, which she could not have afforded because of her economic needs. An invasion of the United States by a European power was out of the question:
from "The American Way of War" Russell Weigley, 1973, page 168-169
who by the way is considered one of the greatest American military historians.
He is drawing from Reports to the Secretary of War, 1884, John Bigelow, Page 54-55, 1968 which is a compilation of reports made to that office over the period.
In other words, next time someone says the British can invade North America with a huge army point this out.
Note that shipping does include horses, artillery, bridging equipment, wagons, ammunition in quantity, forage etc
A typical steamer is about 3,000 tons in this era (as a high average), about double this size as of 1920, with liners of course being larger still (but they don't move cargo, only troops)
So in other words, if you need 135 steamers to move 33,000 troops, that works out to be 405,000 tons of shipping. That includes the 15,000 or so horses and mules, their wagons and artillery, and usually about 30 days worth of food for the men, far less for the mounts.
A horse typically eats about 4 times what a man eats (usually factored as 3 pounds a day for a man, about 5 when you count storage containers etc). In other words, 20 pounds per day per animal, or 200 tons per day for the corps. Horses can graze, but only when it is available, and European and Eastern North American horses are larger than Mustangs or other wild horses because they are raised on grain. Without grain they get sick and die pretty quickly
There is a reason the British didn't use a lot of cavalry or heavy artillery in their wars in North America. The logistics alone explain it.
Now of course you can ferry those troops over one corps at a time to friendly ports, which reduces your immediate lift requirements. But each corps is adding more and more logistical requirements which of course will require still more troops.
All of that is the main reason the US wasn't too concerned about being invaded during the 19th Century or later
Also consider what a heavy or light cavalry brigade would require, or for that matter a division or corps. You quickly begin to see how the American advantage of rail road capacity becomes very important. If nothing else, the Americans can move a vast amount of forage for their animals while the British have to haul most of theirs from Europe and then find a way to move it around Canada.
Later on, as armies acquire more motor vehicles, that massive requirement for fodder is reduced. HOWEVER, there is no oil production in Canada until late in the 20th Century, so every drop of gasoline and motor oil has to be brought across the Atlantic from tankers, which of course require tankers moving oil from the British sources of oil (Persia until later in the century) while the Germans would have to buy from Baku and Ploesti (assuming either of the nations involved are willing to sell). The Americans of course are awash in oil from California, Pennsylvania, Texas, Oklahoma and later on Louisiana. (being the largest exporter until after World War II)
The US Navy was one of the early pioneers of submarine warfare. It would be an expensive business for the invaders to get fuel across the Atlantic
"In the late 19th Century, two steamers were considered to be required to transport a regiment of infantry on a long voyage. For a division of 10,000 men, a least 30 steamers were calculated to be required; for a corps of 33,000 men, 135 steamers. No nation except Great Britain and possibly France possessed enough ships to carry 50,000 troops across an ocean.
In theory, Great Britain might have transported 500,000 men; but that would have required all her shipping, which she could not have afforded because of her economic needs. An invasion of the United States by a European power was out of the question:
from "The American Way of War" Russell Weigley, 1973, page 168-169
who by the way is considered one of the greatest American military historians.
He is drawing from Reports to the Secretary of War, 1884, John Bigelow, Page 54-55, 1968 which is a compilation of reports made to that office over the period.
In other words, next time someone says the British can invade North America with a huge army point this out.
Note that shipping does include horses, artillery, bridging equipment, wagons, ammunition in quantity, forage etc
A typical steamer is about 3,000 tons in this era (as a high average), about double this size as of 1920, with liners of course being larger still (but they don't move cargo, only troops)
So in other words, if you need 135 steamers to move 33,000 troops, that works out to be 405,000 tons of shipping. That includes the 15,000 or so horses and mules, their wagons and artillery, and usually about 30 days worth of food for the men, far less for the mounts.
A horse typically eats about 4 times what a man eats (usually factored as 3 pounds a day for a man, about 5 when you count storage containers etc). In other words, 20 pounds per day per animal, or 200 tons per day for the corps. Horses can graze, but only when it is available, and European and Eastern North American horses are larger than Mustangs or other wild horses because they are raised on grain. Without grain they get sick and die pretty quickly
There is a reason the British didn't use a lot of cavalry or heavy artillery in their wars in North America. The logistics alone explain it.
Now of course you can ferry those troops over one corps at a time to friendly ports, which reduces your immediate lift requirements. But each corps is adding more and more logistical requirements which of course will require still more troops.
All of that is the main reason the US wasn't too concerned about being invaded during the 19th Century or later
Also consider what a heavy or light cavalry brigade would require, or for that matter a division or corps. You quickly begin to see how the American advantage of rail road capacity becomes very important. If nothing else, the Americans can move a vast amount of forage for their animals while the British have to haul most of theirs from Europe and then find a way to move it around Canada.
Later on, as armies acquire more motor vehicles, that massive requirement for fodder is reduced. HOWEVER, there is no oil production in Canada until late in the 20th Century, so every drop of gasoline and motor oil has to be brought across the Atlantic from tankers, which of course require tankers moving oil from the British sources of oil (Persia until later in the century) while the Germans would have to buy from Baku and Ploesti (assuming either of the nations involved are willing to sell). The Americans of course are awash in oil from California, Pennsylvania, Texas, Oklahoma and later on Louisiana. (being the largest exporter until after World War II)
The US Navy was one of the early pioneers of submarine warfare. It would be an expensive business for the invaders to get fuel across the Atlantic