Zanesville is a city in and the county seat of Muskingum County, Ohio, United States. The population was 25,586 at the 2000 census.Zanesville was named after Ebenezer Zane, who had constructed Zane's Trace, a pioneer road through present-day Ohio. He settled in the area in 1797 with his son-in-law, John McIntire, at the point where Zane's Trace met the Muskingum River.From 1810-1812, the city was the second state capital of Ohio. The National Road runs through Zanesville as U.S. Route 40. Novelist Zane Grey, a descendant of the Zane family, was born in the city.The city has two engineering landmarks: the Muskingum River Parkway and its 160-year-old navigation system, designated a National Historic Civil Engineering Landmark; and the Zanesville Y-Bridge, the only such structure in the United States and listed on the National Register of Historic Places.