From "The Witherspoons of Western Pennsylvania" by Evelyn Potter Park, 1968, p. 28:

Mary H. Witherspoon was born March 19, 1831 and died April 6, 1905 at Aledo, Illinois. Married in 1854 to Henry Huffman who was born in 1822 in Washington County, Pennsylvania and died on his farm April 9, 1907 at the age of 85. Mary H. Witherspoon was born at Frankfort Springs, Pa., daughter of John and Margaret (Kennedy) Witherspoon.
The following account of this family is found in "History of Mercer County, Illinois" H. H. Hill & Co., Chicago, 1882, Page 256:
"Henry Huffman (Millersburg Township) farmer and stock raiser, Aledo, was born in Pennsylvania in 1824 and is the son of Henry and Charity (Feazel) Huffman, both natives of Pennsylvania and residing in Washington County. The former died in 1827, age 45 and the latter in 1845, age 52. They were members of the Methodist Church and were quiet, well-to-do and highly respected people in their community.
"Henry Huffman came to Mercer County in the fall of 1854 and located at Keithsburg, where he resided until the following spring, when he located in Section 25, Millersburg Township, where he has since lived. He was married in 1854 to Mary Witherspoon, a native of Pennsylvania, born in 1831, daughter of John and Margaret (Kennedy) Witherspoon. They were members of the Presbyterian Church, known as Seceders. They were peaceable farmers and highly respected citizens. Mr. Huffman has six children ... He and wife are members of the United Presbyterian Church. He has a farm of 208 acres located one-half mile from the east line of Millersburg Township and four miles from the county seat."

Claudia Walter sent the following information:
Children of Mary Witherspoon and Henry Huffman:
1. John Luther Huffman b. ca 1855 Died at age seven.
2. Madison Byard Huffman b. Sept. 3, 1857 d. Sept. 12, 1915.
3. Samuel Ira Huffman b. May 15, 1859 d. 1920 m. Mar. 10, 1892 to Jennie Teal. Removed to Punta Gorda, Florida in Feb. 1898.
4. Dora H. Huffman, (twin) b. Aug. 23, 1864 d. May 12, 1935 near Aledo, Illinois.
5. William E. Huffman (twin) b. Aug. 23, 1864 d. 1927
6. George W. Huffman b. 1869 d. 1946/7
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Note from Darrell Brown:

Mary and Henry Huffman moved to Illinois soon after they were married in 1854 and they acquired farmland in the NE quarter of section 25 of Millersburg township, near Aledo in Mercer county. The 1860 census shows they had a young German immigrant working on their farm named Theobald Gross, but in 1861 he joined the union army. Soon afterwards Mary returned to Pennsylvania to visit her family. She came back with her niece, Margaret Ann Morehead, who came with her to teach school in Illinois. About this time Theobald Gross was discharged from the army because he had lost an arm in battle. After attending Monmouth College for a year, he took up a teaching position and courted Mary’s niece Margaret Ann. In 1864 they were married and eventually developed a farm in Mercer county. After this another niece came from Pennsylvania to Mercer county, Margaret Ann's sister Mary "Clemmie" Morehead, and she married a young farmer in Mercer county named John Irwin Reed.

Of Henry and Mary's children, the only one who married was Samuel Ira. He married Jane "Jennie" Teal. They had two daughters in Illinois, then moved to Punta Gorda, Florida, sometime between 1896 and 1900.

Mary and Henry Huffman lived out their days on their farm and passed it on to their unmarried son George and daughter Dora, who farmed it all their days as well.