Edit in JSFiddle

<div class="container">

    <article class="caption">
        <img class="caption__media" src="http://farm7.staticflickr.com/6088/6128773012_bd09c0bb4e_z_d.jpg" />
        <div class="caption__overlay">
            <h1 class="caption__overlay__title">Alaska</h1>
            <p class="caption__overlay__content">
                Alaska is a U.S. state situated in the northwest extremity of the North American continent. Bordering the state is Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia (specifically, Siberia) further west across the Bering Strait.
            </p>
        </div>
    </article>

</div>

/*
 * Housekeeping
 */
body {
    font: normal 16px/1.5 Arial, sans-serif;
}

h1, p {
    margin: 0;
    padding: 0 0 .5em;
}

.container {
    margin: 0 auto;
    max-width: 480px;
}

/*
 * Caption component
 */
.caption {
    position: relative;
    overflow: hidden;

    /* Only the -webkit- prefix is required these days */
    -webkit-transform: translateZ(0);
            transform: translateZ(0);
}

.caption::before {
    content: ' ';
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: transparent;
    transition: background .35s ease-out;
}

.caption:hover::before {
    background: rgba(0, 0, 0, .5);
}

.caption__media {
    display: block;
    min-width: 100%;
    max-width: 100%;
    height: auto;
}

.caption__overlay {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    padding: 10px;
    color: white;

    -webkit-transform: translateY(100%);
            transform: translateY(100%);

    transition: -webkit-transform .35s ease-out;
    transition:         transform .35s ease-out;
}

.caption:hover .caption__overlay {
    -webkit-transform: translateY(0);
            transform: translateY(0);
}

.caption__overlay__title {
    -webkit-transform: translateY( -webkit-calc(-100% - 10px) );
            transform: translateY( calc(-100% - 10px) );

    transition: -webkit-transform .35s ease-out;
    transition:         transform .35s ease-out;
}

.caption:hover .caption__overlay__title {
    -webkit-transform: translateY(0);
            transform: translateY(0);
}