Shows the marriage (at home) of the daughter of a moderately prosperous Pennsylvania farmer in the late 1810s. The bride's wedding dress would probably be used as her regular "Sunday best" dress for the next year or so (note that the hem of her dress is an inch or two above the ankle, as was practical for even the Sunday-best dress of a farmer's wife -- while a special-purpose wedding gown, which generally only the rich wore, would probably be floor-length and/or with a train trailing behind). She happens to be wearing a white dress, but wedding dresses were very commonly of other colors also during that period. (The artist might have put the bride in white just to ensure that she's the natural visual focus of attention.)

The bridesmaid is holding the bride's right glove, which she's taken off so that she can clasp the groom's hand directly skin-to-skin (something which at the time would be considered an inappropriate display in many other contexts, but not here).

Symbolic lovebirds are in a cage above the bride and groom. The cat is hiding away on top of the cupboard. The whip-like thing that the little boy is holding is actually for spinning children's tops very fast.

Here's some commentary which accompanied an engraving of the painting that was printed in the Analectic Magazine in 1820:

The Country Wedding is engraved from a painting by Krimmel, an artist not sufficiently known to be duly appreciated. He is a native of Germany, but long since chose this country for his residence, and has painted many pictures in which the style of Wilkie -- so much admired in England -- and Gerard Dou so much celebrated of yore -- is most successfully followed. He avoids the broad humor of the Flemish school as much as possible, as not congenial to the refinement of modern taste, and aims rather at a true portraiture of nature in real, rustic life.

In the picture here presented he has delineated a scene of no rare occurrence in the dwelling of our native yeomenry. The whole is in admirable keeping. The furniture and decorations of the rooms, the costume and attitudes of the characters show perfectly the inside of a farmer's dwelling, and the business that occupies the group. The old clergyman appears to have just arrived, his saddlebags, hat and whip, lie on the chair near the door, the bride stands in all her rustic finery, rustic bloom and rustic bashfulness. The bride-groom's hand on her shoulder, seems intended to revive her courage, while the manner in which he grasps her hand is at once affectionate and awkward. The distress of the mother solaced by the father, who points to the younger daughter, as if indicating her as the successor to her sister's rank in the family, is well expressed. And the by-play at the door, which is opened by a servant girl to admit an old woman, the awkward affectation of grace and importance in the bride's-maid, whose attention seems to be attracted by what is passing between the young man and young woman on the other side of the room, all are full of life and true character of painting.

Mr. Krimmel's painting room, in Spruce street above Seventh, in Philadelphia, contains many admirable specimens in the same style. His country dance, Return from camp, Return from boarding school, &c. afford the amateur a rich and varied repast.