troops and supplies had to be raised quickly. The media played a prominent role in starting both wars—theMaine's sinking was really the result of an internal explosion and Britain and France portrayed Germany as "the Hun" of Europe. Theodore Roosevelt was also featured in both wars: he was a combatant in the Spanish-American War and an advocate for joining WWI.

There were several differences in American involvement in the wars. The United States gained territory as a result of the Spanish-American War; Wilson made a point of not asking for any territory as a result of WWI. The Spanish-American War was between two nations; WWI involved many combatants. WWI killed over 250,000 Americans; the Spanish-American War killed significantly less. WWI was also more expensive; the US sent its munitions and money long before the first soldier arrived in France. The US used rationing and the draft during WWI—these were not needed during the Spanish-American War. The US also fought against Filipino freedom fighters after the Spanish-American War; after WWI, the troops mainly returned home.

When comparing and contrasting the Spanish-American War and World War I, the differences are much more apparent than the similarities. For starters, the American war with Spain was a short conflict that lasted just under four months. WWI lasted for four years. The Spanish-American War also saw fewer combat-related deaths, which were measured in the hundreds. Sometimes more people would die in a single day during WWI than during the entirety of the Spanish-American War. The death toll of WWI may be as high as 22 million. The Spanish-American War was primarily between two countries, while WWI was a conflict between large alliances. Tactics were much different, too. WWI was mostly fought along static entrenched locations. Fighting forces in the Spanish-American War were much more mobile.

As for similarities, both wars were ignited by independence movements. The earlier war started when the US got involved in the Cuban independence movement. WWI began after the assassination of the Austro-Hungarian heir to the throne by Serbian freedom fighters. Both wars also made great use of propaganda to portray the enemy as a barbarous and the fight as a noble patriotic effort. Both conflicts also saw the end of empires as the losers lost most of their imperial holdings. Incidentally, both conflicts ended with peace treaties signed in France.

Although both wars were fought to preserve the independence of free countries, the conflicts of WWI and the Spanish-American War led to very different consequences. In contrast to the Spanish-American War, WWI led to wide political changes in Europe, the development of new war weapons, and a change in the American social landscape. WWI was also a very expensive war that led to many more casualties than the Spanish-American war.

It has been said that WWI caused the deaths of 9 million combatants and 5 million civilians. It also cost $300 billion in direct and indirect costs, more than any previous war in history. WWI also led to the fall of four autocracies: Russia in 1917, Turkey in 1922, Austria-Hungary in 1918, and Germany also in 1918. Russia sustained great losses during WWI, and it never fully recovered from it. The losses caused Czar Nicholas II to lose his control over the Russian government. Read how the losses Russia sustained during WWI led to the February and Bolshevik Revolutions of 1917.

WWI also led to the fall of the Ottoman Empire (Turkey) in 1922 and affected political changes in the Middle East that has reverberated to modern times. Although Turkey/The Ottoman Empire chose to remain neutral in the beginning, it eventually decided to enter the war on the side of the Central Powers. The Empire sustained insurmountable losses because of the war, and it never recovered its dominance again. After WWI, British forces dominated regions in the Middle East that later became modern-day Iraq, Syria, Lebanon, Jordan, and Israel.

Also, read about the fall of Germany after WWI and how WWI led to the fall of the Habsburg-ruled Austria-Hungarian Empire, resulting in the forming of new nations such as Czechoslovakia and Yugoslavia. 

In terms of new technological advances in war weapons, read about new war weapons that led to Allied victory in WWI and ten of the deadliest weapons during the war.

Last, but not least, WWI also ushered in a new technological era and social adjustment in the United States. The exodus of people into cities led to more people participating in the excesses of the Roaring Twenties. Indeed, unlike the Spanish-American war, WWI led to wide-ranging political and social changes that continue to affect our modern age.

In order to get a better answer, it might be helpful to ask a more focused question.  There are many aspects of these wars that could be compared and contrasted.  Here are a few points that you could make:

• The Spanish-American War was a tiny war that lasted a short time.  WWI was a huge war that lasted a long time.
• The Spanish-American War was caused largely by a desire in the US for empire and a desire to prove the "masculinity" of the US in war.  People like Theodore Roosevelt thought that the US needed to fight a war to toughen its people and to prove that they were strong.  WWI was caused in part by somewhat different factors.  It was caused by militarism, nationalism, and competition for power between various European countries.  One aspect of this competition for power did involve imperialism, so that aspect of the causes of WWI is similar to a cause of the Spanish-American War.

Outside of the causes, these two wars are rather different because of the huge differences in how big they were.