HTML

CSS:

.container {

    width: 650px;

    height: 650px;

    border: solid 1px red;

    .column {

        width: 30%;

        height: 90%;

        border: 1px solid blue;

        float: left;

        margin-top: 5%;

        margin-left: 1%;

        .column-header {

            background: gray;

            border: solid 1px black;

        }

    }

}

jQuery:

var handleResize = function () {

    var maxHeight = 0;

    $(".column-header").css("height", "initial");

    $(".column-header").each(function () {

        if ($(this).height() > maxHeight) {

            maxHeight = $(this).height();

        }

    });

    $(".column-header").height(maxHeight);

};

$(window).resize(handleResize);