Which group of country gained the most from entry of texas? who lost the most?

Look at this photograph taken during the battle of guadalcanal

"but let us admit texas, and we shall place the balance of power in the hands of the texans themselves. they, with the southern states, will control the policy and the destiny of this nation; our tariff will then be held at the will of the texan advocates of free trade. are our friends of the north prepared to deliver over this great national policy to the people of texas? " - rep. joshua giddings, ohio, may 21, 1844 this quote points to what major issue in the years leading up to the civil war?

The soldiers in the novel use the phrase "it all looked good on paper" several times throughout their experiences. what does this mean in the context of the war?