Question: What ocean was both the Erie Canal and Portage Canal connected to at one point?

Context paragraphs:
Schoharie Crossing State Historic Site: 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.

Portage Canal: The Portage Canal was built to connect the Fox River and Wisconsin River at Portage, Wisconsin along the Fox-Wisconsin Waterway.  For a time, it completed a route from the north Atlantic Ocean, through the St. Lawrence Seaway and down the Mississippi River to the Gulf of Mexico, and back to the Atlantic.

Fox–Wisconsin Waterway: The Fox–Wisconsin Waterway is a waterway formed by the Fox and Wisconsin Rivers. First used by European settlers in 1673 during the expedition of Marquette & Joliet, it was one of the principal routes used by travelers between the Great Lakes and the Mississippi River until the completion of the Illinois and Michigan Canal in 1848 and the arrival of railroads.  The western terminus of the Fox–Wisconsin Waterway was at the Mississippi at Prairie du Chien, Wisconsin.  It continued up the Wisconsin River about 116 miles (187 km) until reaching Portage, Wisconsin.  There travelers would portage to the Upper Fox River, or eventually, use the Portage Canal.  It continued about 160 miles (257 km) down the Fox River, following it through Lake Winnebago and continuing on the Lower Fox over 170 feet (50 m) of falls to the eastern terminus of Green Bay.

Saint Lawrence River Divide: The Saint Lawrence River Divide separates the Great Lakes Basin from the rest of the Atlantic Ocean watershed.  Two canals cross the divide: The Chicago Sanitary and Ship Canal crosses the Chicago Portage and connects Lake Michigan to the Mississippi River watershed.  The Erie Canal connects Lake Erie to the Hudson River watershed.  Historically there were additional canals, e.g., the Ohio and Erie Canal, but most of these are no longer in operation.

Erie Canal: The Erie Canal is a canal in New York that is part of the east–west, cross-state route of the New York State Canal System (formerly known as the New York State Barge Canal).  Originally, it ran 363 mi from Albany, on the Hudson River, to Buffalo, at Lake Erie.  It was built to create a navigable water route from New York City and the Atlantic Ocean to the Great Lakes.  When completed in 1825, it was the second longest canal in the world (after the Grand Canal in China) and greatly affected the development and economy of New York, New York City, and the United States.

Erie Canal Lock 52 Complex: 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.

Pennsylvania and Ohio Canal: 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.

Keweenaw Waterway: The Keweenaw Waterway is a partly natural, partly artificial waterway which cuts across the Keweenaw Peninsula of Michigan; it separates Copper Island from the mainland.  Parts of the waterway are variously known as the Keweenaw Waterway, Portage Canal, Portage Lake Canal, Portage River, Lily Pond, Torch Lake, and Portage Lake.  The waterway connects to Lake Superior at its north and south entries (upper and lower portage entry lighthouses), with sections known as Portage Lake and Torch Lake in between.  The primary tributary to Portage Lake is the Sturgeon River.

Chemung Canal: The Chemung Canal is a former canal in New York, United States.  The canal connected Seneca Lake at Watkins Glen to the Chemung River at Elmira, New York.  It was planned to connect the Finger Lakes region and Pennsylvania's Susquehanna River watershed with New York's Erie Canal system.  The latter connected the Great Lakes with the Hudson River and ultimately the Atlantic port of New York City.

Low Bridge (song): 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.

Supporting paragraphs: Erie Canal Portage Canal
Answer: Atlantic