A manual for writers of research papers, theses, and dissertations, Ninth edition - Kate L. Turabian 2018

Check your introduction, conclusion, and claim
Revising your draft
Research and writing

Your readers must recognize three things quickly and unambiguously:

✵ ▪ where your introduction ends

✵ ▪ where your conclusion begins

✵ ▪ what sentences in one or both state your claim

To make the first two clearly visible, you might insert a subhead or extra space between your introduction and body and another between the body and conclusion. (Chapter 10 discusses revising your introduction and conclusion in detail.)