Other
Airports
2
Police
2
Railroad stations
2
Air mail service
1
Airplane equipment
1
Airplanes
1
Amusement parks
1
Amusement rides
1
Armories
1
Banks
1
Beaches
1
Bus terminals
1
Business panics
1
Church buildings
1
City & town halls
1
Demonstrations
1
Farmers' groups
1
Festive decorations
1
Holidays
1
Military camps
1
Monuments & memorials
1
Parades & processions
1
Pickets
1
Piers & wharves
1
Political parades & rallies
1
Political parties
1
Public buildings
1
Radiophones
1
Riot control
1
Roller coasters
1
Socialism
1
Swimming pools
1
Taxation
1
Traffic congestion
1