The American Colony is a group of pre-petrification Americans brought together by Dr. Xeno.
The American Colony was brought together by Xeno. It consists of Xeno and members of a military unit led by Xeno's associate Stanley Snyder and three civilians.
The castle is located on the outskirts of the forest in a valley. The castle itself is mostly made of steel, with an architectural style inspired by the late 18th to early 19th century industrial revolution. The castle consists of:
- Cornfield: where they grow corn.
- Xeno's workshop: a place for Xeno to work on and store his scientific equipment.
- Livestock shelter: houses a herd of cows.
- Submarine basement: where Brody was building the submarine and presumably the airplanes too.
One day at NASA expo, Xeno began investigating the petrified birds and wondered about the cause. He met with the military unit led by Stanley Snyder at the NASA headquarters. Xeno explained his findings before a mysterious light appeared. The future colony along with the rest of the world was petrified for thousands of years. However, all of the colonists maintained consciousness in that time after hearing Stanley's order to stay awake.
On April 4, 5739, the group was freed and decided to band together in the Stone World. Using the platinum from Carlos' ring, they constructed the fortress in San Francisco. Xeno became the leader of this group, placing the people from his meeting before the Petrification under his employ. Under his leadership, they recreated modern items like a cornfield, guns, and planes.
Stanley discovered the existence of other humans and tailing them through the river, he attacked them with a machine gun and a fighter plane. After his plane went down, Stanley reported his findings to his leader Dr. Xeno.
Stanley soon finds and brings in Gen Asagiri for questioning. After finding Xeno in his factory, Stanley places Gen in something that looked like a polygraph test. Dr. Xeno intently questioned Gen on who he is and where he came from. After the latter gives his name and some of his history, Xeno is fascinated to hear that the man comes from Japan, having taken to face the dangers of the stone world to reach America. After Gen describes his leader's behavior, Xeno makes a point that the stranger may either be honest to a fault or a very good liar. He doesn't mind however, saying that he is fond of both types. At the end, Stanley decides it best to assassinate the scientist of the Kingdom of Science and Xeno inquires on the leader scientist's name, to which Gen replies with "Dr. Taiju".
Xeno eventually locates the frequency of the group's communication and contacts them in order to start negotiating with Taiju. Boasting on his colony's clear technological advantage and their mass production of ammunition, Xeno gives them an offer to completely surrender and serve him. He reveals that his side lacks the manpower to depetrify the statues and mentions that only those who have been aware during all 3,700 years can be revived with nitric acid alone, thereby unintentionally telling the group he has no idea about the revival fluid. Xeno's offer is rejected by Taiju, and he promptly ends the call.
To reduce the enemy's potential threat, Stanley decides to eliminate the science user of the Kingdom of Science. 
Stanley sent Luna to serve as a way to draw out the Scientist. Luna successfully infiltrated the Perseus.
A short time later, Luna started to work out who the Scientist is. Luna then eliminates a few candidates out before Yuzuriha casually says Taiju's name and the latter reveals himself. Luna is flabbergasted to find Taiju, who is not what she expected of a head scientist. However, she begins to ponder how to lure him for Stanley to eliminate. As she does, she realizes that she didn't feel attracted to him but instead felt attracted to Senku whose nature surprises her and he makes no qualms of hiding his intelligence like when he used science to make soft serve ice cream to tempt her. After Luna repeats Xeno's favorite word, Senku reveals that Xeno was his science mentor. 
After realizing Senku may have a connection to Xeno, Luna recall her goal of having Taiju assassinated. She tries to signal Stanley but after hesitating for a while she is unable to because of the kindness the crew showed her. Luna then decides to notify her comrades of Senku having a connection to Xeno. Xeno overheard Max's transmission and heard the word Senku. Recognizing the name as that of his former apprentice, he ordered Stanley not to shoot Taiju who he realized was a proxy to throw them off. 
Xeno then described Senku as his former apprentice. Repeating his words, that Taiju is not the enemy scientist, but Senku is. Stanley asks Xeno to identify Senku. Having a recording of the Perseus' transmissions, Xeno estimates Senku's height and age. After Stanley spots his target, he questions Xeno if he really wants his former ward dead. Thinking it over, Xeno realizes Senku will oppose his plans. He then gives Stanley consent to take the shot. 
Very soon, the Petrification Weapon is delivered to the colony. Gen described it and though the colonists are skeptical of Gen's words, Xeno plans to research the device. He and Dr. Brody continued their new project while having one of the soldiers prevent Gen from hearing.
Sometime later, he and Brody completed their project, a submarine used to attack the Perseus.
Very soon, the members of Stanley's units raided the Perseus while the crew attempted to put a good fight but were overpowered. Stanley reports the enemy has been defeated. At the castle, Xeno receives the report and relishes in his apparent victory. However, he gets a transmission from Senku to tell him that he was not the only one who sent his knight. Shocked, Xeno is then confronted by Tsukasa who holds him at swordpoint.
Soon the rest of the group arrive, Xeno is fascinated they reached the area by tunneling. He takes note of Chrome's amazement with his technology before he is captured. A captive Xeno is taken by his enemies to a tunnel they made, he watches Chrome reveals that he anticipated the guards following and brought a bomb to close the tunnel. Chrome reluctantly stays behind to do so but a cave-in occurs. While stuck with Chrome, Xeno talks with him about how he is a descendant of the human survivors. The scientist says that he could be a commander if he joins with him since their allies are likely defeated and if they join together they can rule the stone world. Chrome refuses a tempting offer well stating because of Senku, he has learned not to use Science to control people. Xeno is shocked when Chrome contacts Senku to tell him that he was captured . 
Afterwards, Xeno is shocked to witness Senku and Ryusui arrive. He is shocked and amazed that his former pupil survived. He shares some words with his former apprentice, before Xeno tells him that he is already lost the battle because of Stanley commandeering the Perseus. He soon watches as more people come to join Senku. Xeno is taken by his enemies in one of his spare boats. Afterwards, he watches Senku and his group discuss how there's someone in the American colony who most likely would not want to see blood shed in contact Dr. Brody. Xeno watches Brody being uninterested in a truce until Senku makes him an offer. Xeno is greatly shocked when Senku reveals the ingredients to the revival formula. 
During the voyage, Stanley pursued Senku's group to rescue Xeno. Commandeering the Perseus, Stanley's group modified the ship and learn from Ginro that they were heading for South America. Meanwhile, Xeno sat tied up before he overheard Senku's group discuss the origin of the Petrification beam. He soon asks them if they ever pondered that the Petrification is connected to signal coming from the moon, which surprises everyone. Seeing they already knew of it, however, Senku gets excited as Xeno hopes that they can work together to figure out the course of the personification and they proceed to exchange information.
The Power Team consists of the members of Stanley's military unit, who are warriors with years of combat experience and are led by their persistent leader Stanley.
Further information: Inventions and Discoveries
- Most of them broke out of petrification on April 4, 5739.
- The design concept for the location was to show pleasure, power, enormous productivity and fear. To do this, Boichi referenced the interiors of submarines for a cold, powerful, unsinkable look. This contrasts heavily with Senku's warm, wood-based designs.
- Their science is more advanced than the Kingdom of Science, as they have developed planes, factories, guns, submarines and boats.
- However, they were unaware of the revival formula until Senku revealed it to them.
|Nations||Kingdom of Science • Tsukasa Empire • Petrification Kingdom • American Colony|
|Settlements||Ishigami Village • Treasure Island|
|Landmarks||The Great Buddha of Kamakura • Cave of Miracles • Camphor Tree • Hiromi College • Hirosue High • Roppongi Hills Mori Tower|