Robert Wilson Lowber Rasin was born on October 17, 1836, in Coursey Point, Queen Anne's County, Maryland.

He was a chemist, merchant, and businessman. He attended Loyola College, Baltimore. He was interested in chemistry and became affiliated with the Philadelphia Guano Company and later the Sombrero Guano Company. He worked as a manager for Capt. Edward K. Cooper, the discoverer and owner of Navassa Island and its vast guano deposits. The island was sold to the Navassa Phosphate Company and Rasin became its general agent. In 1872, he resigned from the position to found the R. W. L. Rasin & Co., active in the United States, Europe, and South America. As the head of the company, he became renowned as a chemical expert. Rasin was instrumental in developing the fertilizer business all over the world and in educating the farming community in its use. In 1881, he was elected president of the Chemical and Fertilizer Exchange of Baltimore. Loyola College conferred upon him the degree of Ph.D.

In 1860, he married Margaret Ann Johnson (1832-1899), and circa 1900, he married A. S. Ruth. He died on March 18, 1905, in Baltimore, Maryland.