In 1797, he remitted land as payment to his son-in-law, John McIntire (1759–1815), at the point where Zane's Trace met the Muskingum River.Zanesville and Putnam (eastern side of Muskingum River), from the 1840s until the American Civil War broke out, was part of the Underground Railroad.In excess of 5,000 Union soldiers, along with hundreds of townsfolk, were stationed in the Zanesville area to protect the city in 1863 during Morgan's Raid.[citation needed] After the Civil War, the city grew in size and gained prominence in the State for manufacturing and textiles.From the 1820s until the 1970s, downtown Zanesville was the premiere economic center of the city with various factories, offices, small to large stores, many hotels, over a dozen stages and movie theaters, nearly twenty churches, and nearby neighborhoods (inhabited mainly by persons of Irish or German ethnicity).The National (Cumberland) Road and its successors U.S. Route 40 and Interstate 70 cross the Muskingum at Zanesville.This characteristic was due to a history of racial intermixing dating back to the role of Zanesville as a stop on the Underground Railroad.A three-way bridge called the "Y-Bridge" spans the confluence of the Licking and the Muskingum rivers.Listed on the National Register of Historic Places, it is one of few bridges of its type in the United States.Its unique shape led pilot Amelia Earhart to describe Zanesville as "the most recognizable city in the country".[citation needed] The city is served by Zanesville Municipal Airport, built during World War II, and opened near the end.Interstate 70 and U.S. Route 40 (which closely follows the path of the older National Road), pass through Zanesville and run roughly parallel to each other.