Joseph Warren Crossman (1830 - 1850) was the son of William Crossman (1790 - 1839) and Olive (Lyon) Crossman (1787 - 1879); the youngest of their 8 children.
The tombstone shown in the cover photo is in the Clarendon Flats Cemetery, erected by Joseph's family as a memorial to him. Joseph had died in 1850 and been buried in the Yerba Buena Cemetery in San Francisco, CA. He no doubt had traveled to California to make his fortune in the gold rush of 1848 - 1855. How long he had been there and whether he ever made it to the gold fields is not known, nor what he died of.
The Yerba Buena Cemetery was just established the year Joseph died and was closed in 1871 to make way for the San Francisco City Hall. Graves were supposed to have been moved to the Golden Gate Cemetery which is also now defunct, having become Lincoln Park in 1909. Whether Joseph's remains were moved to the Golden Gate Cemetery or not is not known, nor where they are in the modern day Lincoln Park if they were relocated.
See the Curtis House entry in the Homes collection for information about Wolcott Curtis (1812 - 1854) who also went to California to make his fortune, and as occurred with Joseph Crossman, Wolcott died in California too.
See the DeWitt Clinton Gaskill, California Gold Rush entry in this collection for the story of another man from Clarendon who sought (and found) his fortune in California.
See the A History Unearthed, Henry Hunter Crossman entry in the Artifacts collection for the life story of his brother Henry (1823 - 1877). See also the Crossman House entry in the Homes collection for the ancestral Crossman homestead that Joseph grew up in.