_Names._ _Length._ Missouri 4,400 Mississippi 3,000 Arkansas 2,100 St. Lawrence 2,000 Mackenzie 2,000 Del Norte 2,000 Nelson 1,500 Columbia 1,500 Red River 1,500 Platte 1,500 Ohio 1,350 Kansas 1,200 White River 1,200 Tennessee 1,100 Alabama 650 Savannah 600 Potomac 550 Connecticut 410 Hudson 324 Delaware 300 SOUTH AMERICA. Maranon 4,500 La Plata 3,000 Madeira 2,500 Orinoco 1,800 Tocantins 1,800 Ucayale 1,600 St. Francisco 1,500 Paraguay 1,400 Xingu 1,400 Topajos 1,300 EUROPE. Volga 2,040 Danube 1,710 Don 1,050 Dnieper 1,080 Kemi 780 Rhine 670 Elbe 570 Loire 540 Vistula 500 Dniester 480 Tagus 580 Dwina 480 AFRICA. Nile 2,687 Senegal 950 Orange 900 Gambia 700 ASIA.