Question: Which canal was longer -- the Miami and Erie Canal or the Riverside Canal?
Context: The popular song "Low Bridge, Everybody Down" was written in 1905 by Thomas S. Allen after Erie Canal barge traffic was converted from mule power to engine power, raising the speed of traffic.  Also known as "Fifteen Years on the Erie Canal", "Fifteen Miles on the Erie Canal", "Erie Canal Song", and "Mule Named Sal", the song memorializes the years from 1825 to 1880 when the mule barges made boomtowns out of Utica, Rome, Syracuse, Rochester, and Buffalo, and transformed New York into the Empire State.  The tune is sadly nostalgic. The New York State Canal Corporation is responsible for the oversight, administration and maintenance of the New York State Canal System, which consists of the Erie Canal, Cayuga–Seneca Canal, Oswego Canal and Champlain Canal.  It is also involved with the development and maintenance of the New York State Canalway Trail and with the general development and promotion of the Erie Canal Corridor as both a tourist attraction and a working waterway. The New York State Canal System (formerly known as the New York State Barge Canal) is a successor to the Erie Canal and other canals within New York.  Currently, the 525 mi system is composed of the Erie Canal, the Oswego Canal, the Cayuga–Seneca Canal, and the Champlain Canal.  In 2014 the system was listed as a national historic district on the National Register of Historic Places in its entirety, and in 2016 it was designated a National Historic Landmark. The Riverside Canal is an irrigation canal in El Paso County beginning southeast of El Paso, Texas.  The canal acquires water from the Riverside Diversion Dam on the Rio Grande 15 mi southeast of El Paso.  The canal is managed by the US Bureau of Reclamation.  The canal extends for 17.2 mi with a capacity of 900 cubic feet per second.  Water from the canal irrigates about 39,000 acres (160 km²).  The canal and diversion dam is the southernmost system on an irrigation project extending along the Rio Grande in New Mexico and Texas.  The canal supplies a canal network extending throughout the Upper Rio Grande Valley. The Pennsylvania and Ohio Canal, also known as the P & O Canal, the Cross Cut Canal and the Mahoning Canal was a shipping canal which operated from 1840 until 1877 (though the canal was completely abandoned by 1872).  It was unique in that it served to connect canals in two states (the Ohio and Erie Canal in Ohio and the Beaver and Erie Canal in Pennsylvania) and was funded by private interests. The Miami and Erie Canal was a canal in Ohio that ran about 274 mi ; it was constructed from Cincinnati to Toledo to create a water route from the Ohio River to Lake Erie.  Construction on the canal began in 1825 and was completed in 1845 at a cost to the state government of $8,062,680.07.  At its peak, it included 19 aqueducts, three guard locks, 103 canal locks, multiple feeder canals, and a few man-made water reservoirs.  The canal climbed 395 ft above Lake Erie and 513 ft above the Ohio River to reach a topographical peak called the Loramie Summit, which extended 19 mi between New Bremen, Ohio to lock 1-S in Lockington, north of Piqua, Ohio.  Boats up to 80 feet long were towed along the canal by mules, horses, or oxen walking on a prepared towpath along the bank, at a rate of four to five miles per hour. Erie Canal Lock 52 Complex is a national historic district located at Port Byron and Mentz in Cayuga County, New York.  The district includes two contributing buildings (the Erie House and the blacksmith shop / mule barn); three contributing engineering structures (Erie Canal Lock 52, culvert, and canal prism of the enlarged Erie Canal); and archaeological sites associated with the canal operations.  Lock 52 was constructed 1849-1853 as part of the Enlarged Erie Canal program.  It remained in operation until the rerouting of the canal under the New York State Barge Canal System in 1917.  The Erie House was built in 1894 and is a two story frame structure that housed a saloon and hotel. The Miami and Erie Canal Deep Cut is a preserved, 6600 ft long, segment of the Miami and Erie Canal, United States.  In order to avoid using locks to go over a ridge, the canal was dug deeply into the ridge, far more than the 5 ft depth of the canal itself.  Workers dug the canal bed up to 52 ft into the blue clay ridge that separated the St. Marys and Auglaize River watersheds.  It is a United States National Historic Landmark. Schoharie Crossing State Historic Site, also known as Erie Canal National Historic Landmark, is a historic district that includes the ruins of the Erie Canal aqueduct over Schoharie Creek, and a 3.5 mi long part of the Erie Canal, in the towns of Glen and Florida within Montgomery County, New York.  It was the first part of the old canal to be designated a National Historic Landmark, prior to the designation of the entire New York State Barge Canal as a NHL in 2017. The Walhonding Canal was a canal in Coshocton County, Ohio that was used as a feeder canal for the Ohio and Erie Canal.  A small canal, at only 25 mi long, it was wholly contained within Coshocton County, following the Mohican River from Cavallo south to the confluence with the Kokosing River, which together with the Mohican forms the Walhonding River.  The canal followed the Walhonding River southeast toward Coshocton where it met the Ohio and Erie Canal in Roscoe Village.
Answer: The Miami and Erie Canal