How did william h. seward aid us expansion? seward sent missionaries to hawaii to spread us culture. seward concluded the first us treaty with japan. seward negotiated the end of the russo-japanese war. seward signed a treaty with russia to buy alaska?

William H. steward was appointed to be the secretary of state by president Abraham Lincoln in 1861 and served up to march 1869. He was crucial as he managed international affairs during the civil war and also negotiated the 1861 purchase of Alaska. In addition he was also an antislavery activist in the whig and republican parties before the civil war. He aided US expansion by signing a treaty with Russia to buy Alaska. 

He sign the treaty with russia to buy alaska