The Portland & Ogdensburg Railroad was a railroad planned to connect Portland, Maine to Ogdensburg, New York. The plan failed, and in 1880 the Vermont section was reorganized and leased by the Boston & Lowell Railroad. In 1886, the Maine and New Hampshire section was reorganized as the Portland & Ogdensburg Railway. That part was leased to the Maine Central Railroad in 1888, and in 1912 the Maine Central leased the eastern part of the Vermont section from the Boston & Maine Railroad, the successor to the B&L.

Ogdensburg is a city in St. Lawrence County, New York, United States. The population was 10,436 at the 2019 census. In the late 18th century, European-American settlers named the community after American land owner and developer Samuel Ogden. The city is at the northern border of New York at the mouth of the Oswegatchie River on the south bank of the St. Lawrence River. The only formally designated city in the county, it is located between Massena, New York to the east and Brockville, Ontario to the west.