Americans tend to have smaller tombs now than even a century ago. Why is this significant? What artifacts do we want buried with them today?
The tendency to have tombs at all, versus smaller burial plots in a cemetery, represents some shifting values and traditions in American culture that reflect perhaps a more modern, and sometimes less religious, approach to death and funerals.
Mausoleums, crypts and large, ornate headstones and family plots are still more common in Europe than America, and in 1900 America was awash in new European immigrants. They brought these traditions with them, and in the generations since, it is not surprising to see a shift in attitudes, and smaller gravestones and markers.
Also, cremation is much more common and popular as a burial choice than it was then, and it is more likely people will be buried in a large cemetery as opposed to on their own land. They are more likely to be buried in a professional funeral ceremony as opposed to by their own relatives, in graves dug by hand. In general, Americans are not as traditionally religious as they were in 1900 too.
Still, many people like to have personal items buried with them, such as photos, mementos, things the person enjoyed in life, which could range from playing cards, to cigars, to photos to a baseball. Contrast this with more ancient burial items such as Egyptian servants, jewels and gold.