The USA has it all: vast land spaces, a potential influx of immigrants, a small but nice industrial base, and a difficult to challenge position for growth in the world.
The USA is potentially a superpower, but in 1836 it has a long way to go, colonial entanglements with the UK need settling to allow for expansion westwards, Mexico threatens from the south, and the UK from the north.
Overcoming these initial challenges opens the gates to the most difficult and traumatic challenge of all: the Civil War. If the USA pursues its anti-slavery agenda, the secession of the South is inevitable, and if the South is not beaten, then the failure and potential collapse of the USA is at hand.
If you take up the manifest destiny of this great nation, and succeed in reunifying the divided house, then Superpower status beckons.
The USA is home to practically all the resources you will ever need, but you will still need to do some World Market meddling to acquire the machine parts you'll need.
If you want to pursue a more militaristic path, build at least four cavalry divisions as soon as you can. Then use those divisions to grab claims in north America from the UK and Russia. Later on, those cavalry divisions will be useful in wars with Mexico. The USA can also pursue a more peaceful strategy. If you want to pursue this path, build up your industry and try to purchase territory from Mexico through an event.
- On day one trade a claim for the Oklahoma claim of Texas. This allows you to claim a colony, and thus get to #1 spot on prestige, which should get you a few extra machine parts on the WM.
- Then move your Dragoons to Colorado and send them as an exp. force to Texas. Take Mexico's two colonies. Return control of the exp. force to yourself, and you can again trade with Texas to get Colorado. Texas will lose the war and eventually apply for statehood, thus granting you back the claims you traded to her.
The best strategy that I've found for dealing with Mexico at the start of the game is to take a pretty low key approach. One potential strategy is to declare war just long enough to steal their claims in Colorado and Oklahoma and then make a quick peace. If you want to avoid this entirely, you can just stay neutral and let them annex Texas. Don't worry -- revenge will come later when your ready to fight. Just don't let yourself be sucked into a prolonged war with the Mexican states, if you can avoid it. At the start of the game, they are almost as powerful militarily as the United States, and the time and money that it will take to defeat them is much better spent on your initial infastructure and building up your reserves.
Alternative Opening: Beat Mexico Into Submission
For those who want a very exciting beginning, they can beat Mexico into submission in the first year of play. First, ally with Texas when you start the grand campaign. Transport your army by ship to provinces that border Texas. Mexico will declare war. Mexico has a great advantage in having a larger army, but suffers disadvantage in having a laughable navy. Your winning strategy is based upon the mobility of your navy. To win, you must use your navy to land soldiers in Mexico's undefended coastal provinces. Land, occupy, reboard ships, repeat again. Attack where they are not; defend when terrain favors you. As you take enough of the coastal provinces, Mexico's army will be drawn away from Texas. If you want to be devious, capture the province just north of Mexico's capital, thereby separating the bulk of Mexico's armies from their capital. When it is time, assault the capital with your artillery units with general Scott leading the way. If you are lucky, the Mexican army will go suicidal and throw their armies piecemeal into the meat grinder of your artillery in a vain attempt to prevent you from capturing their capital. For any extra units, use them to capture south Mexico. Be sure to get the precious metal mines of Zacatula. Now, it's negotiation time. Demand land, lots of land, especially Zacatula's gold mine. Coffee and dye provinces aren't too bad either.
Peace will come upon the USA, but wait, Texas is still fighting. If you don't feel this is too gamey, transfer your army divisions to Texas. You can even do this while your army is inside Mexico. Texas will win and likely gain some territory they otherwise wouldn't have. Whatever Texas gains, you gain when Texas is admitted as a state in the union.
With the end of war, Mexico will hopefully be so unhappy with you they will declare war again at some later point. That's good. You can capture even more precious metal mines from Mexico.
Optional Objective: Liberate Canada
The United States failed to seize Canada in 1812, but that doesn't mean that the US will stop trying. If you are able to get military control of every province of Canada's two easternmost regions, then an event will fire that will liberate the nations of Canada and Quebec as either dominion or satellite, your choice.
The best way to start is to guarantee independence of China. When UK declares war on China, you will join China's side in a colonial war against UK. You will then have the chance to send your calvary flying everywhere stealing UK's claims to Canada. You might not have enough time to take every claim, but you should get enough claims to frustrate UK's ability to claim colonies.
Thereafter, the strategy becomes much harder. The only way I was able to win was to be friendly with France, and have France guarantee my independence. Then I rejected the 49th parallel which caused UK to declare war. France joined the war on my side. While UK was busy fighting France, I was busy taking over Canadian provinces. Unfortunately with the liberation of Canada, I no longer had a war score with which to negotiate with UK. I had to take over UK's Atlantic possessions and kick UK out of France to make a sufficient war score to end the war on favorable terms.
This strategy is very hard. The Brits will hate your guts thereafter and declare war on you whenever opportunity strikes, like when your defense pact with France expires. At one point, I was fighting a war with Russia, Ottoman Turks, Netherlands, and UK.
Midgame Strategies -- Between 1836 and the Civil War
The United States has a large initial starting population that balloons late game. You can take advantage of this in several ways. First, make sure that your country always has the maximum number of available divisions in reserve, or at least very close to it. By the time the civil war comes around, you should have around 100 divisions in reserve to fight the south (making for a very short war once they're fully mobilized) and you can easily have over 450 reserve divisions by the end of the game. If you can remember to increase them on time, about every six months. This should help your war score as well, since each division counts four points towards overall military strength.
Britain is pretty easy to deal with in most games. Generally, they have other aspirations than fighting a colonial war against the United States. I always accept the 49th parallel when offered. They slight increase in land that you get is rarely worth having to fight the world's largest super power. However, the prestige from capturing the extra colonies may be worth it as prestige is usually the one obstacle to the United States winning the game in 1920.
The Civil War
The Civil War shouldn't be much of a problem, if you've succeeded in building your reserves before that time. Once war is declared, mobilize fully and you should be able to crush the south in a few months with your 100+ divisions. I've never had the civil war last more than a year using this strategy.
Once your divisions are mobilized, if you haven't done so yet, you should consider attacking Mexico and taking back your land. Probably the easiest way to do this is to just leapfrog your divisions south and take their capital. Then, build a wall with troops and take the southern provinces until you have enough war score to satellite them. By this time, your divisions should be good enough and large enough to rout any Mexican division that isn't dug in, especially with your numerical superiority.
Alternative strategy: Civil War
Alternatively, you can do without the mobilization of reserves. CSA army starts out small enough to be manageable by your regulars. Just position your regulars at Washington DC. When war breaks out, capture Richmond and seize the surrounding countryside. Attack unoccupied provinces; defend on favorable terrain. Use your navy to shuttle troops to capture CSA coastal provinces. Try not to destroy the CSA army. After the CSA surrenders, the CSA army units becomes yours.
Post Civil War
After the civil war, the United States should begin to have a huge influx of immigrants from Europe. Use these immigrants by building factories in which ever state begins to accumulate unemployed pops (use F6 to figure this out). Likely, it will be California. Also build capitalist when you have the chance since they tend to make tons of money.
With your rapidly expanding industry and the resulting surplus of money that it brings, I would think towards colonization as a source of potential prestige. My likely target there would be a south-east Asian nation with -100 prestige (to avoid you losing 100 prestige when you declare war). Build a base there and use it for colonial expansion. You can convert pops in your nonessential production provinces (i.e, grain) to soldiers and get manpower for a rapid colonial expansion. Just make sure not to accumulate to many bad boy points too quickly or you might have someone like Russia or France trying to take away your colonies. Annexing a uncivilized nation about every five to seven years, combined with your high military score that comes from constantly expanding your reserves, should keep the superpowers at bay.
End Game Strategies
Once the Spanish-American war comes, you should be able to defeat the Spanish troops without too much difficulty. Use your superior navy to blockade Manilla, Cuba, and Puerto Rico and attack the dug in Spanish with from at least three directions at once with armies at least five times larger and the fight should go quickly. If you're feeling really ambitious, you could even consider satelliting Spain.
The main obstacle to the United States winning the game will probably be prestige. Typically, the United States (playing with a conservative strategy without too much aggression and minimal play other than just building railroads and factories) should finish in the top two for industry (a constest between them and Germany) second in military power (behind the vast armies of Great Britian) and in the top five for prestige. In order to actually win the game, the United States needs to raise their prestige score to within 500 points of Germany (who should have the highest prestige score after German reunification). To do this, the United States could trade claims for techs and then fight colonial wars for the remainder. This is the hardest part for the United States and probably the main limiting factor as to why they don't win the game.
Another strategy is to use your huge profit that your industry should be bringing in to build Dreadnoughts by the dozens. This will help up your war score and will probably compensate for some of the lack of prestige that you have.
Good luck building your American Empire!