The natives of the planet Mars, known as the Martians are (along with Humans) the most intelligent species in the Sol system. After contact with Harry Truman, several Martians had begun living on Earth, with mixed results in many countries.
The first race, classified as "Red Martians" look similar to Humans, aside from a slight copper tint in their skin. Their biology is also similar to that of humans, as they bear live young and have similar internal organs.
The so called "Green Martians" are the second most dominant race of Mars. They have tusks on their faces, green skin and four arms. Studies have shown them to be oviparous, capable of laying eggs.
The Red Martians were the first species to develop their own civilization, known as Kelsat. However, because of the constant internal fighting, the Kingdom fell after a few centuries. Over time, several smaller kingdoms sprung up, many of which were constantly fighting with each other.
Invasion of the Greens
Around 160 BC, the nomadic Green Martians invaded several Red Martian Kingdoms. Though they managed to sack several, some Kingdoms joined together against the invaders.
Led by the Kingdom of Quey, they managed to subdue the Green Martians and enslave them. This continued until 885 AD, when the Monarch of Helium passed a resolution which freed their slaves and elevated them to citizenship.
Contact with Earth
In 1947, a group of five, comprised of three Red Martians and two Green Martians, set out on their first landing of their neighboring planet, Earth. However, engine sabotage caused the shuttle to crash-land in the town of Roswell in New Mexico. The pilots were soon taken into care and met with the President Harry Truman.
In 1950, one of the Martian leaders contacted President Truman and requested the transport of several Martian civilians. Debate in Congress led to the transport of at least 10 Million Reds and 5 Million Greens to the United States.