Robert Augustus Barnes, born November 29, 1808, was a grocer, commission merchant, banker, real estate investor, and philanthropist. He was born in Washington D.C. and moved to Louisville, Kentucky at the age of thirteen after the death of his father. Robert was raised in Louisville by his uncle, Richard Barnes. In 1830, Robert Barnes moved to St. Louis and worked at a mercantile house for two years until, at the age of just 23, he established his own grocery and commission company. He did business throughout the Southern and Midwestern United States and found great financial success through his business endeavors and investments in stocks and real estate.

Barnes became the president of the State Bank of Missouri in the early 1840s. During his twenty-six years as the bank's president, Barnes maintained his involvement in various businesses and organizations throughout St. Louis, including the St. Louis Railroad Company. It was Robert Barnes, in his role as bank president, who approved the loan request of a young Adolphus Busch, who would in turn use the loan money to expand the Anheuser-Busch Brewery into a national powerhouse.

In 1845 Barnes married Louise DeMun, from the prominent DeMun family of St. Louis. They had two children, neither of whom survived infancy. Robert Barnes died April 2nd, 1892, two years after his wife, Louise. With no surviving heirs, Barnes dedicated much of his estate to philanthropic endeavors, with his most notable contribution being the $850,000 he dedicated to the creation Barnes Hospital. His goal was to build "a modern general hospital for sick and injured persons, without distinction of creed..." Construction began on Barnes Hospital in 1912 after investments had grown the bequest to nearly $2 million. A partnership with Washington University influenced the design of the hospital buildings, leading to the creation of labs and classrooms to help Barnes Hospital fulfill its role as a teaching facility for medical students at Washington University. The hospital was completed in 1914 and opened that same year. In his will, Barnes requested that the hospital's director place a memorial wreath on Barnes's grave each year, a tradition which has been carried out with little interruption since the hospital's founding.