Answer:
After your sentence you should put "Most of these wars led to substantial
economic changes throughout US history."
Step-by-step explanation:
This will add to your first idea and make it flow through 2 sentences.
Introduction - be sure to introduce the topic and make at least 2 sentences containing the same idea. Your introduction should contain a thesis statement and a hook. Once you enter another idea in your intro be sure to add a transition word.