Lacy's Fort, also known as Fort Lacy, the fortified home and trading station of Martin Lacy on the Old San Antonio Road, was an important staging point for military operations during the late 1830s and early 1840s. It was located just off what is now State Highway 21 and two miles southwest of Alto in eastern Cherokee County. Lacy, who arrived in Texas in 1827 and served for a time as Indian agent for the Mexican government, evidently moved to the site before the Texas Revolution and established a trading post. Some sources claim that he built the fortifications before 1835, but later research suggests that it was not erected until around 1838. Fearing attack from Kickapoo and Biloxi Indians during the Córdova Rebellion in August 1838, Lacy abandoned the post and sought shelter on his farm, forty-five miles to the southwest. He returned a short time later and evidently began to construct defensive fortifications-probably a log blockhouse and stockade-that he called Fort Lacy.
In 1838 and 1839, during the campaign to suppress the Córdova Rebellion, the fort served as an operations and supply base for the Third Militia brigade commanded by Maj. Gen. Thomas J. Rusk. In December 1838 Capt. Joseph Daniels's Milam Guards also stopped briefly at Lacy's. During the Cherokee War in 1839 the fort was again the site of considerable activity, as hundreds of militiamen and volunteers from East Texas and rangers from Galveston and Houston passed through on their way to Camp Johnston and Fort Kickapoo. In September of that year the fort served as a rendezvous point for volunteers preparing to march to Fort Houston on the campaign that ended on October 16 with the battle of the Kickapoo Village. In July 1840 a small garrison of regular soldiers from Fort Skerrett camped there before moving onto the western frontier. With the expulsion of the last uncooperative Indians from East Texas, however, Fort Lacy had outlived its usefulness. Lacy apparently began to dismantle the fortifications around 1841 or 1842. The settlement retained its name until 1849, when nearby Alto was founded. Within a short time most of the residents had moved to Alto, and by the early 1850s the fort site was evidently abandoned. The Texas Centennial Commission placed a marker at the site in 1936.