Argos is a town in Green and Walnut townships, Marshall County, Indiana, United States. The population was 1,777 at the 2020 census. In 1833, Sidney Williams arrived in the area which is now Marshall County and purchased 600 acres of land on the present day site of Argos. Mr. Williams built a tavern, an inn, and helped build a section of Michigan Road. M…Argos is a town in Green and Walnut townships, Marshall County, Indiana, United States. The population was 1,777 at the 2020 census. In 1833, Sidney Williams arrived in the area which is now Marshall County and purchased 600 acres of land on the present day site of Argos. Mr. Williams built a tavern, an inn, and helped build a section of Michigan Road. Mr. Williams sold his land to Clark Bliven, the man who built the courthouse on the Williams's land. This local place of rest wasn’t considered a town until some time later. On January 8, 1851, John Pleak and Marquis L. Smith, laid out the town of Sidney, which is the predecessor to Argos. The town of Sidney was named in honor of Sidney Williams.