JSFiddle - React, Tailwind, and code Playground

HTML

<div id="col1" class="col">
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla non sodales dui. 
    Pellentesque eu orci sed dolor imperdiet rutrum et ut orci. Sed vulputate fermentum 
    augue, eget porta nibh pulvinar quis. Nam eget arcu porta elit tempus consectetur. 
    Vestibulum sodales bibendum libero id accumsan. Praesent quis nisl non enim bibendum 
</div>
<div id="col2" class="col">
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla non sodales dui. 
    eu orci sed dolor imperdiet rutrum et ut orci. Sed vulputate fermentum augue, 
    eget porta nibh pulvinar quis. Nam eget arcu porta elit tempus consectetur. Vestibulum 
    sodales bibendum libero id accumsan. Praesent quis nisl non enim bibendum EXTRA EXTRA 
    EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA 
    EXTRA EXTRA EXTRA EXTRA EXTRA EXTRA 
</div>
<div id="col3" class="col">
    <button id="makeEqual" onclick="checkHeights();">Make Equal</button>
    <div id="result"></div>
</div>

CSS

.col{
    margin:0px 10px 0px 0px;
    background:#eee;
    width:150px;
    float:left;
}

JavaScript

var tallest=0;

$('#makeEqual').click(function(){
    $('.col').each(function(){
        if($(this).height() > tallest)
           tallest = $(this).height();
    });
    $('.col').css('height', tallest + 'px');
    $('#result').html('Tallest Column: ' + tallest  + 'px');
});