Simplify the following text for a Grade 10 native English-speaking person.
Original: The history of the Constitution of Australia began with moves towards federation in the 19th century , which culminated in the federation of the Australian colonies to form the Commonwealth of Australia in 1901 .
Simplified: The history of the Constitution of Australia began with moves towards federation in the 19th century . This led to the Australian colonies joining together to form the Commonwealth of Australian 1901 .