Built step pyramids and buried the massive offerings in la venta.

The Olmecs built step pyramids and buried the Massive Offerings in La Venta.

Explanation:

The Olmecs were a Mesoamerican people who dominated the area of the Gulf of Mexico at the time of Maya's entry on the stage around 2000 BC.  

They created the Olmec culture in ancient pre-Columbian Mesoamerica that grew in the tropical areas of south-central Mexico during its pre-classical period. In what is now the Mexican states of Veracruz and Tabasco, Olmec culture flourished in the area between about 1500 and 400 BC and is believed to be the forerunner of all Mesoamerican civilizations that developed later.

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation: