I am using Bootstrap 3 and added a tooltip to my div. I've tried using < br > \n and 
 to create the new line. Would it be a problem with the Bootstrap stopping me?
<div class="content show-tooltip" data-placement="top"
data-original-title="1st line of text <br> 2nd line of text">
You need to add data-html="true"
to the markup..
<div class="content show-tooltip" data-html="true" data-placement="top"
title="1st line of text <br> 2nd line of text">
Working demo: https://codeply.com/p/C8083WXo5Z
For Bootstrap v5: data-bs-html="true"
<div data-bs-html='true' data-bs-toggle='tooltip'
data-bs-title='1st line <br> 2nd line'>