Law and legislation 6,606 Bridges 5,977 Commerce 4,064 History 1,851 Railroads 1,719 Appropriations and expenditures 1,488 Interstate commerce 1,418 Ships 1,361 Officials and employees 1,217 Harbors 1,181 Budget 1,045 Transportation 978 Finance 940 Lighthouses 940 Government policy 878 Claims 805 Electronic commerce 770 Navigation 711 International trade 704 Research 675 Economic conditions 664 Selection and appointment 637 Governmental investigations 582 Safety measures 580 Bills, Private 564 Rates 552 Expenditures, Public 545 Consumer protection 535 Prevention 525 Dredging 500