JSFiddle - React, Tailwind, and code Playground

HTML

<div id="staffscroll">
    <div class="person">1</div>
    <div class="person">2</div>
    <div class="person">3</div>
    <div class="person">4</div>
    <div class="person">5</div>
    <div class="person">6</div>
    <div class="person">7</div>
    <div class="person">8</div>
    <div class="person">9</div>
    <div class="person">10</div>
    <div class="person">11</div>
    <div class="person">12</div>
    <div class="person">13</div>
</div>

CSS

.clearFix {
    border: 1px solid black;
}

JavaScript

var start = 0,
    $list = $('#staffscroll .person').slice(0, 6);

while ($list.length) {
    $list.wrapAll('<div class="clearFix"></div>');

    start += 6;
    $list = $list.end().slice(start, start + 6);
}