What were the weaknesses of the U.S.'s enemies during the Spanish American War?

The major weaknesses of the Spanish during the Spanish-American
War were that they had fewer soldiers and a weaker navy.

As an
example of this, the Spanish navy had only 6 ships to defend Cuba. It also had very few ships in
the Philippines. This was because Spain chose to keep its ships at home to protect the Spanish
homeland. This allowed the US to easily destroy the Spanish navy both in Cuba and at Manila Bay.
This also meant that the US could prevent supplies from reaching
Cuba.

Partly because of this, and partly because Spain was not very
wealthy, the Spanish had relatively few soldiers, especially in Cuba. This meant that American
forces, even though they were fairly amateurish and very disorganized, could easily defeat the
Spanish army in Cuba.