James Green McDonald, Jr., a leading figure in Grimes County's Democratic party in the late nineteenth and early twentieth centuries, and a chief organizer and leader of the White Man's Union Association of Grimes County, was born in Anderson, Texas, on September 11, 1858, the fourth child and oldest son of Julia T. (Davis) and James G. McDonald, Sr., a prominent Grimes county lawyer. James G. McDonald, Jr., seems to have been determined to follow in the footsteps of his father whom he greatly admired. He studied law under his father, was admitted to the bar in 1888, and the next year began his own legal practice. Like his father, he also became active in the county's Democratic party and rose quickly in its ranks. In 1884 McDonald was appointed Anderson's postmaster (then a federal Democratic political appointment); in 1890, when he was thirty-two years old, he was elected county attorney; and he was elected county judge in 1892 and 1894. Though he had no property and little personal wealth of his own at the time, to the new Judge McDonald the future no doubt seemed bright. Then, in Grimes County elections in 1896 and again in 1898, a coalition of White Populists and Black Republicans combined to defeat the Democrats in relatively close contests for sheriff, county judge, and other local positions.
In early 1899 McDonald, who had been ousted from his position as county judge in 1896 and was defeated again in 1898, began to work with a group of other local Democrats to prepare for the election of 1900. At a meeting in McDonald's office, they agreed to form a new organization, the White Man's Union Association of Grimes County (WMU) to take the county back from their Black and White Populist opponents. Apparently inspired by the Jaybird Association, a similar organization created earlier in Wharton County, the Grimes County WMU drew up an all-White slate of candidates, headed by James G. McDonald, Jr., for county judge, for the 1900 elections and worked hard to rally support for their cause: the complete elimination of Black influence in county politics. Meanwhile a campaign of terror was waged to suppress the opposition. Two Blacks had been lynched in the county just before the WMU was formed; by the spring of 1900 night riders were roaming the county, threatening Blacks and telling them to leave the county. In July Jim Kennard, a local Black Populist leader, was shot and killed a hundred yards from the county courthouse in Anderson. No one was ever charged with the murder, but it was rumored that McDonald was responsible. In late September another prominent Black Populist, Jack Haynes, was shot to death in his cotton field. Again, no one was ever charged with the crime.
The intimidation campaign worked. Thousands of Blacks and an unknown number of White Populists left the county in the months before and after the election. Over 4,500 men, White and Black, had voted in the 1898 Grimes county elections. In November 1900 only about 1,800 voters showed up at the polls. In Plantersville, just north of Anderson, the Populist vote dropped from 256 in 1898 to 5 in 1900; in Anderson, the Populist candidates received about 13 votes each. All of the WMU candidates, including McDonald, were swept into office in a huge landslide victory. After the election of 1900, the WMU's control of local politics was assured. The county's Blacks had been effectively stripped of their right to vote, and the Populist movement in the county had been crushed. In 1902 the WMU's candidates for Grimes county offices would run completely unopposed, and the Grimes County WMU and the Democrats would continue to control the area's elections for the next sixty years. McDonald served as judge of the Grimes County Court from 1900 to 1904 and was elected on Grimes County's WMU ticket to the Texas state legislature in 1906 and 1908. More than 30 percent of the Blacks in Grimes County left the area between 1900 and 1910. In 1910, for the first time since 1850, more Whites than Blacks lived in the county.
During his years in office after the 1900 election, McDonald's real estate holdings and personal wealth grew considerably. As he gradually acquired more land and livestock, his total taxable wealth grew steadily—rising to $3,620 by 1903, to $3,816 by 1904, to $4,325 by 1906, and to $7,048 by 1908. In 1910 he owned eleven town lots, 455 acres of land, twenty-two horses or mules and thirty-seven cattle, with a total assessed value of $6,500. J. G. McDonald, Jr., married Eleanor Stone, Henry Fanthorp's grandaughter, in 1895. They probably moved into the former Fanthorp Inn about 1901, and in 1903 they had a daughter, Mary Eleanor. But Eleanor died January 25, 1903, not long after the birth, and only a few months later, on June 15, Mary died. McDonald's father, James G., Sr., died that same year, on March 11. McDonald never remarried and continued to live in the former Fanthorp Inn for more than thirty years after Eleanor's death. After leaving office in 1909 he withdrew from public life to tend to his properties and his horses.
McDonald was an amateur historian and became respected in Grimes County for his knowledge of the past; during the 1920s and 1930s he was consulted by local historians such as Irene Taylor Allen and Eric Lee Blair on a number of topics, including the origins of the White Man's Union. In his role as a chief organizer and beneficiary of the formation of the WMU, McDonald had helped to shape the development of Grimes county politics and its social relations. In his later role as a respected local historian, he found himself in a position to shape how his actions would be understood and interpreted for generations to come. In 1919 he returned to the state legislature to represent the Twenty-second District. In 1928 McDonald was elected as the WMU's candidate for Grimes county attorney, and he held the post until 1932.
In his later years McDonald's behavior grew increasingly eccentric, and in 1935 friends grew alarmed as they witnessed ever more erratic behavior. He was examined by Dr. M. E. Parker who later testified that McDonald was "suffering from Senile dementia, hallucinations, imagined people were plotting after him. Unquestionably of unsound mind." At a competency trial held on September 4, the court also heard George Nobles who had known McDonald for about twelve years. "[I] saw him 2 weeks ago," Nobles testified. "[M]ental condition getting worse, talks about fights, etc., hard time going to sleep—now talks constantly about things of the past." McDonald was committed to the Austin State Hospital, where he died in March 1938. He is buried in the Fanthorp Cemetery in Anderson.