JSFiddle - React, Tailwind, and code Playground

HTML

<div class="equalheight">The quick brown fox jumps over the lazy dog.</div>
<div class="equalheight">How razorback jumping frogs can level six piqued gymnasts! How razorback jumping frogs can level six piqued gymnasts!</div>
<div class="equalheight">Now is the time for all good men to come to the aid of their country. </div>

CSS

.equalheight {
    float: left;
    width: 100px;
    background-color: green;
    border: 1px solid blue;
}

JavaScript

$(document).ready(function() {
    var maxheight = $.map($('.equalheight'), function(val, i) {
        return $(val).height();
    }).max();
    $('.equalheight').height(maxheight);
});

Array.prototype.max = function() {
    return Math.max.apply(Math, this);
};