In which year were the first ten amendments proposed to the states?
12 amendments were proposed to the states in 1789 and 10 were ratified.
In 1787, the "Founding Fathers" got together and began work on creating a constitution. The form of government they created had never been tried before, with the 3 branches, the checks and balances, and the like.
When the document was done, there were a few people who couldn't bring themselves to sign off on the document because it lacked a Bill of Rights (in fact, one of the people who refused to sign was the author of the Virginia Bill of Rights).
Even without their vote of approval, the Constitution was approved by the committee and sent to the states for ratification. Again, there were states that argued the Constitution shouldn't be ratified and for the same reason - there should be a Bill of Rights.
Patrick Henry, he of the famous "Give me liberty or give me death" speech, argued that the Bill of Rights was dangerous and shouldn't be included - that there was no point in saying that there is a Freedom of Assembly when there was no power given to the government in the Constitution to infringe on the power to assembly in the first place.
Nevertheless, once the Constitution was ratified, a Bill of Rights was started. The States submitted 189 suggestions, James Madison boiled them down to 17, and Congress approved 12. The 12 were submitted to the States in September of 1789, they ratified 10 of them. The Bill of Rights went into effect in December of 1791.