There is a single photograph of the interior of a covered wagon in one of my reference books; but from the jumble of items within, I would guess it to be an emigrant wagon from a period rather later than the 1840ies. It seems to contain rather a jumble of furniture: an upholstered wing chair, a spinning wheel, a very elaborate trunk fitted out with a number of smaller drawers for silverware: the trunk is open, displaying a fine mid-Victorian assembly of knives and silverware. There are a couple of inlaid boxes— portable desks or sewing tables, what appears to be the head and footboard to a Jenny Lind bed, a butter churn and a lighted kerosene lantern hanging from the center, mid-peak of the inside. The series of hoops holding up the canvas cover is reinforced with a pair of horizontal lathes along the sides of the wagon, from which hang an number of articles of clothing; some dresses, a shirt, a baby's dress and a couple of sunbonnets. This may be a wagon in which a family lived during their journey, late in the days of the emigrant trail. In this wagon interior, there is very little glimpse of what a typical emigrant wagon would have had to have carried in the opening days of the trails to Oregon and California, when the only possible means of re-supply along the way, other than hunting and gathering, were at Ft. Laramie and Ft. Hall.
The greatest part of the goods carried in a typical emigrant wagon was food. Assuming a six-month long journey, an early guidebook writer advised 200 lbs of flour, 150 pounds of bacon, 10 pounds of coffee, 20 of sugar and 10 of salt per each adult, at a minimum; a schedule providing a monotonous diet on variants of bread, bacon and coffee, three meals a day. More elaborate checklists afforded a little more variety, not to mention edibility, suggesting such things as dried, chipped beef, rice, tea, dried beans, molasses, dried codfish, dried fruit, baking soda, vinegar, cheese, cream of tarter, pickles, mustard, ginger, corn-meal, hard-tack, and well-smoked hams. Common sense suggests that all sorts of light-weight preserved foods and epicurian luxuries would have been included also, to ward off the boredom of bread/bacon/coffee. Canned food was a science still in the experimental stage then and such things were expensive and heavy, and seldom included. A number of resourceful families brought along milk cows, and thus had milk and butter for at least the first half of the trail. Recommended kitchen gear included an iron cooking kettle, fry-pan, coffee pot, and tin camp plates, cups, spoons and forks, and considering that coffee featured a s a major food group, a coffee grinder. Small stoves were sometimes brought along, but more usually discarded as an unnecessary weight.
Prior to the great Gold Rush stampede over the trail in 1849, it was possible for those parties which included some experienced frontier hands to eke out their foodstuffs with hunting alongside the trail; buffalo, antelope, sage hen, and from gathering various berries and plums from thickets along the rivers, wild peas, wild onions, and various sorts of greens. Nutritional science may have been only dimly understood, but most emigrants (or at least their wives) had a good grasp on the prevention of scurvy, dysentery and other food related ailments.
Other necessary gear for the wagon itself: water barrels, chains, 100 feet of heavy rope, and spare parts to replace that which was most readily broken, such as tongues, kingbolts, axels and wheel spokes, although such added to the weight, and some emigrants preferred to take a chance on being able to find suitable wood to make a replacement along the trail. The wagon itself was too small for more than two adults or a couple of children to sleep comfortably in, so the overflow would need to be accommodated by a tent, and blankets spread out within them.
Since they would be on their own, as far as repairs of anything at all would be concerned, a veritable tool shop was advised: knives, a whetstone, ax, hammer, hatchet, shoves, saw, gimlet, scissors and sewing supplies to repair canvas and clothing, nails, tacks, thread, beeswax and tallow, twine, washbasins and water buckets. Some comforts were not omitted; candles and lanterns, patent medicines, extra clothing; most emigrants wore the same work clothes they would have worn for a day of work on the farm, or a day out hunting, and perhaps, tucked away in a small corner, some small cherished luxury, a favorite book or a bit of china. Men with a trade took the tools necessary to practice it. Every party also took arms and ammunition, although as it would turn out, most had much less use for them than they had expected.
And as it also turned out, even with all the preparations and supplies, a fair number of the early emigrants arrived in California or Oregon on foot, with little more than what they stood up in, thanks to the difficulties of the trail. Having eaten just about all of their food supplies, jettisoned the non-essential gear, lost their oxen and animals to bad water and the cruelties of the desert, and abandoned their wagons in the desert or high in the Sierras, or along the Snake River - they arrived in the place where they wished to be, carrying their children - and thought it had all been a fair exchange.