What do the red/white bars at the bottom of the window mean?
They indicate the prevailing weather conditions in the main regions. Plenty of red indicates good weather. Note that they're the wrong way round for some reason (Seaboard on the left). Weather affects movement rates and the maximum length of supply lines.
How to locate your garrisons
Select Build Forces, New Corps/Division, select Corps, and select any leader. You will see a list of the garrisoned cities from which you can build new corps or divisions. All cities not listed are ungarrisoned.
This method works at the start of the game. Later on, you should be aware that it won't reveal garrisons in cities where a battle is going on, because you can't create new units there.
You can also click on your own cities one at a time to see whether they have garrisons or not.
How to increase your rail capacity
To increase the number of rail moves that can be made per turn, select National, Supply/Cotton Transfers, and increase the Overall rail capacity. Each increase will cost you 100 supplies, paid by the region with most supplies.
How to make a unit retreat
To make a unit move away from the nearest enemy, it helps to give it a Withdraw order (rather than Advance or Defend), as well as specifying its route.
How to entrench units
In the units orders dialog box you may notice a field called Entrenchment, with an initial value of zero, meaning that the unit is not entrenched.
To be entrenched (Entrenchment = 1 or more) gives a unit an extra advantage in battle, as you might expect.
If a unit is ordered to Defend, it is not given any move order, and it is sitting on its army objective (if any), there is some probability that it will increase its level of entrenchment. As the game goes on, this probability increases, and the maximum level of entrenchment also increases. Both sides learned the value of entrenchments only gradually during the war.
If a unit moves, its level of entrenchment is reset to zero.
Important: in addition to the above, a unit in a city with fortifications automatically gets the same entrenchment level as the number of fortifications. In practice, it's much quicker (though expensive) to increase fortifications than to wait for a unit to entrench itself; and a high entrenchment level (7 to 9) more than trebles a unit's defensive strength, in my experience.
How to attack a heavily fortified city
- If possible, cut it off from supplies and wait at least a few turns while the defenders gradually dwindle without fighting. Don't attack too soon because they can still bite.
- A port city (on sea or river) normally remains in supply even if surrounded on land. You may be able to cut supply by surrounding it on land and patrolling it with a fleet; but it's not certain.
- Use plenty of ships to take out the forts (expect heavy losses), and attack simultaneously on land before the fortifications go back up again.
- If you can't manage either of the above, attack with at least 5:1 odds. Expect heavy losses.
What's the effect of training?
According to some official notes on the game published by Interactive Magic in or before 1998, 1200 Crack troops are equivalent to 4000 Untrained troops. We can speculate that either of these forces may also be well matched by (say) 1800 Veteran or 2700 Trained troops.
Seaborne invasions
One undamaged transport can carry 1500 men or 12 guns, or a mix. It makes no difference whether the men are infantry or cavalry — presumably the horses swim alongside the ship.
Most Confederate ports have fortifications and guns, which will sink Union transports, though the troops may be able to get ashore. The only initially undefended Confederate ports are Brunswick, Jacksonville, St Augustine, and Sabine City.
Sieges
There are two kinds of land combat in the game: battles and sieges. They follow different rules.
A siege occurs when a unit attacks a city defended only by a garrison. In this case the numbers and types of forces on each side, and the city fortifications if any, are counted to determine the result, but the types of weapons and the level of experience of the troops on either side are not counted and make no different to the result.
If the city is fortified, you will need some artillery to take it.
European intervention
In the event of European intervention, British and French warships can be used by the Confederate player as if they were his own. They can even be merged into Confederate fleets.
British and French transports, however, can't be used by the Confederate player to transport cotton or troops; though they can be given simple movement orders. They can be merged with Confederate transport fleets; but this should be avoided because then the whole merged fleet suffers from the same limitations.
The Union player should respond to European intervention by patrolling St George and Nassau and sinking the European ships as they emerge, a few at a time. If this is not done, the Confederate player can form a powerful navy by adding European warships to his own.
Confederate transports can't be used to move European troops from St George or Nassau; it seems that the Confederate player just has to leave those troops there until they decide to move of their own accord.