when did the first immigrants reach america? scientists disagree on the date, but some say it may be much earlier anyone thought. the original americans called "indians" by columbus, were the descendants of immigrants. do you know where they came from and when they first arrived in the americas. when columbus "discovered" america in 1492 he found people already living there thinking he had landed in the east "indies", but they didnot call themselves "indians" stretching from the top of north america to the tip of south america were many different groups. each with its own name way of life. many scientists believe that the ancestors of these people migrated to america from asia about 11500 years ago. at the time the northern half of the earth was covered in ice: a lot of the land that is now under water , was then dry land, experts believe that people from siberia followed the animals that they they hunted and traveled to alaska over land that is now a 50 mile body of water called the bering strain. when did these people migrate to the new world? this is a difficult question to answer exactly. archeologists look for clues in the earth by digging for the remains of these early peoples. Along with bones from humans and animal, they uncover pieces of pottery, tools, and even the remains of campfires. then they use a special technique, called radiocarbon dating to figure out the age of these artifacts by measuring the amount of radioactive carbon in them. recently archeologist have discovered clues at digs in both north and south america that lead then to believe that humans first migrated to the new world not 11500 years ago, but much earlier 20000 or even 50000 years ago these discoveries are causing a lot of excitement and controvers among experts. two of the most interesting sites are in chile and brazil. in monte verde chile scientists working at a dig found well preserved artifacts including stone tools and wooden well-preserved artifacts including stone tools and wooden bowls, they also found a human footprint and the remains of a dwelling that is very similar to a type found in siberia. scientists estimate that humans lived in this place 12500 years ago. Archeologist are now working on another site that be almost 33000 years old. most of the controversy about early settlement is over the site uncovered in pedra furada brazil. archeologist niede guidon found cave paintings dating back 12000 years but she also uncovered charcoal from old campfires and stone tools that she believes are at least 30000 and maybe more than 50000 years old radiocarbon testing supports her findings but some scientists still have doubts. they say that the charcoal could be from general fires in the area and not from compires, and the "tools" could be pieces of naturally formed rock guidon defends her findings and even comes up with a new idea of the early settlers got to america they may have traveleded directly from asia to south america in boats. what will be uncovered next? only time will tell...