What evidence is there that the colonists had already unsuccessfully voiced concerns to the king?

What does your text say? Did the Continental Congress have a representative in London to express grievances? Did the Declaration of Independence enumerate attempts to petition the King and Parliament? What other evidence does your text suggest or describe?

Here are several sites that should help you answer this question. If one doesn't give you the information you want or need, try another one until you find what you want.

http://www.bing.com/search?q=grievances+against+the+king+and+parliament+expressed+by+american+colonists&form=EDGNTC&qs=PF&cvid=18dd65b3cbd1407992d855f607dc25d5&pq=grievances+against+the+king+and+parliament+expressed+by+american+colonists

To find evidence that the colonists had already unsuccessfully voiced concerns to the king, you can follow these steps:

1. Start by researching primary sources from the time of the American colonies, such as letters, diaries, or colonial newspapers. These documents often provide firsthand accounts of the colonists' interactions with the British monarchy.

2. Look for documents that express the colonists' discontent or opposition to British policies. Pay particular attention to letters or petitions addressed to the king or other high-ranking officials.

3. Check for any recorded responses from the British government or the king himself regarding these expressions of concern. These responses could indicate whether the colonists' concerns were acknowledged or taken seriously.

4. Examine historical records of any meetings, debates, or correspondence between colonial representatives and British officials. This includes the writings of prominent figures like Benjamin Franklin, John Adams, or Thomas Jefferson, who often acted as intermediaries between the colonists and the British government.

5. Analyze historical accounts and scholarly works that discuss the relationship between the colonists and the British monarchy. These sources often provide interpretations and analyses of the evidence, helping you understand the context and significance of any failed attempts to voice concerns.

By following these steps and conducting thorough research, you should be able to find evidence that supports the claim that the colonists had already unsuccessfully voiced concerns to the king.