What were the pros and cons of the Spanish conquest of the Americans?

Reasonable chance of success - Only about 3,000 US soldiers died during the war, which is a low number(spanamwar). Total size of US army was about 248,000 soldiers and volunteers. Spanish casualties were around 60,000.

Waged by a legitimate authority - one of the few times war was actually declared using the correct process.

CONS:

America annexed Hawaii.

The US army was not ready to fight in the war. They were understaffed and lacked the skill required to fight.

Citations:

"Casualties." Casualties. N.p., n.d. Web. 28 Apr. 2015. <http://www.spanamwar.com/casualties.htm>.

"The Spanish-American War, 1898 - 1866–1898 - Milestones - Office of the Historian." The Spanish-American War, 1898 - 1866–1898 - Milestones - Office of the Historian. N.p., n.d. Web. 25 May 2015.

"Introduction." - The World of 1898: The Spanish-American War (Hispanic Division, Library of Congress). N.p., n.d. Web. 25 May 2015.

"Resources." PBS. PBS, n.d. Web. 25 May 2015.