What is the importance of the Act of Union in 1841?
Do you mean the Preemption Act of 1841? If so, this law, also known as the Distributive Preemption Act, allowed the sale of public lands at very low prices. It gave the right to squatters, living on government land for at least 14 months, to purchase up to 160 acres for as little as $1.25 per acre. Present territories that would eventually become states--such as Alabama, Arkansas, Illinois, Indiana, Louisiana, Michigan, Mississippi, Missouri and Ohio--would receive 10% of the total sales upon admittance to the Union. It was particularly popular in the territories of Nebraska and Kansas, though claims were greatly reduced after the enaction of the Homestead Act of 1862. The Preemption Act was repealed in 1891. It served to greatly enhance America's dream of manifest destiny during the 19th century.
The Union Act of 1841 joined the English-speaking provinces of Upper Canada and the French-speaking province of Lower Canada into a political union. A new constitution was created by the British North America Act of 1867, which unified “French-speaking Quebec and English-speaking Ontario, along with the previously self-governing British colonies of Nova Scotia, New Brunswick, and Prince Edward Island, into a confederation called Canada.” This confederation of provinces left the majority of governing power remaining with the provinces. The Union has resulted in discord between Quebec and Canadian nationalists with Quebec demanding special treatment within the union to protect the unique culture of the French-speaking province.