It appears Josiah M. Reese did not participate in the 1900 census. In addition to searching several sites (Ancestry, FamilySearch, HeritageQuest), I manually checked each page of the 1900 Census of Davidson, Franklin, Jordan and Muncy Creek, and found several Reese families, but no entry for Josiah and Effie.
There was a Josiah Reese living in Turbot (Turbotville) in 1900 (shown below), about 33 miles southwest of Davidson. There are major discrepancies, yet noteworthy similarities:
Our Josiah M. Reese was born in February of 1832. This Josiah's birth is reported as April of 1828.
Josiah M. Reese's wife was Effie Rachel (Shaner) Reese, who was born in February of 1841. This Josiah was married to Mary, who was born in May of 1833. They report being married 50 years and had 11 children. Effie lived until June 17, 1907 and her headstone was inscribed "Effie, wife of Josiah Reece", so it seems unlikely that Effie and Josiah divorced and Mary was a second wife.
Josiah and Effie had a son named William, like this Josiah did, but he was born in October 1860 and married a woman named Margaret. This William was born in January of 1874 and was married to a woman named Nora.
William and Nora had no children. William and Margaret, however, had four known children born before this census was taken in 1900.
In 1910, Josiah was 78, living in Jordan, Lycoming County, Pennsylvania. He was a widower who owned his own farm. His daughter, Mary, who was 31 and married to James Wilson Kile (age 32), also lived in the home. Mary and "Wilson" had been married 13 years and had four children, three of whom were living in the home: Emma (age 13), Hurley (7), and Eva Kile (1). Josiah died the following year, on June 17, 1911. His daughter, Mary, died in 1942 in Moreland, which is ten miles south of Jordan - the midway between Jordan and Turbot.