[Possibilities]

The population would be larger.

The Indian Wars would have had a lesser impact.

War with France on Mexican border was more probable.

The South would have been industrialized. It was on its way by 1860.

Cuba may have been annexed by war with Spain in the 1860s.

The first transcontinental railroad route would have been between Shrevesport Louisiana and San Francisco, instead of between Omaha, Nebraska and Sacremento, Ca.

Western expansion would have been slower.

Would Robert E. Lee replace General Scott?

Wars with Central and South American countries would have been more probable (like Costa Rica, Nicaragua and Paraguay).

Our military, especially the navy, would have suffered from lack of modernization and Europe would have exceeded ours in modern ships and weapons.

Virginia would still be one state.

We would be using more alcohol based fuels instead of petroleum.

The slavery debate would continue.