You asked if Robert McBeth had kin in or near Henry Co., MO.From my research, I did not find any relatives of Robert McBeth in Missouri.
But, the parents of his wife Mary McLane did live in Henry Co., MO.
In the Henry County Missouri Obituaries, I found:
McLANE, Elizabeth Catherine MOORE - 1829 - 1891 Englewood Cemetery MA-MD, Clinton, Clinton Twp, Henry Co, MO Clinton Eye, Mar 28 1891 - Thursday at 8:30 a.m., the spirit of Mrs. W. H. McLane passed to the realm of the immortals. She was born Feb. 2, 1829 in Bollinger county, this State, and was married to Col. McLane June 19, 1845. They became citizens of Clinton in 1866, highly esteemed members. Mrs. McLane was strictly domestic in her tastes and from choice always superintended household affairs in person and was a perfect helpmate to her children. Four gracious daughters were reared by her, three of whom survive her - Mrs. McBeth, Misses Lydia and Kate. She has been a sufferer for two years from a complication of diseases. Dr. Jennings, her attending physician, says a more patient sufferer he never saw nor pain borne with more Christian fortitude. She was a member of the M. E. Church. Funeral at the residence and burial in Englewood.
McLANE, William H. Col - 1816 - 1898 Englewood Cemetery MA-MD, Clinton, Clinton Twp, Henry Co, MO Clinton MO, Nov 26 1898 - Col. W. H. McLane, one of the oldest pioneers of the county, died at his home on South 2nd Street Tuesday night at 9:30. He was born in 1816 in Cape Girardeau County. He came to Clinton in 1866 and has been a prominent and enterprising citizen. He leaves three children to mourn his loss - Mrs. McBeth, Mrs. Roberts and Miss Kate McLane.