Another large land owner in the Midtown before the Civil War was Peter Lindell, one of two brothers who made fortunes in merchandising. Lindell owned a large midtown tract bounded by Garrison, Laclede, Vandeventer Avenues and Lindell Boulevard, the eastern part of which was heavily wooded and was called Lindell's Grove. It was used for various outdoor gatherings including the annual encampment of the State Militia and for that occasion, in 1861, it was renamed Camp Jackson in honor of the newly elected proSouthern governor of Missouri.
The St. Louis Arsenal was in Union hands at this time and its commandant saw the encampment of the militia with its southern sympathies as a threat to Union control of St. Louis. Captain Nathaniel Lyon, disquised in women's clothing, drove unmolested through the camp to inspect a mysterious shipment thought to be armaments. On May 10, 1861, four thousand Union troops surrounded and captured Camp Jackson without a shot being fired, in the first Civil War action in St. Louis. Later the camp, renamed in honor of Hamilton R. Gamble, became part of a chain of defenses built around the city.