On this day in History - November 18

1493 – Christopher Columbus first sights the island now known as Puerto Rico.

1883 – American and Canadian railroads institute five standard continental time zones, ending the confusion of thousands of local times.

1910 – In their campaign for women's voting rights, hundreds of suffragettes march to the British Parliament in London. Several are beaten by police, newspaper attention embarrasses the authorities, and the march is dubbed Black Friday.

1918 – Latvia declares its independence from Russia.