The trip to Verplancks Point is a huge milestone for Tim. He has been looking forward to it because he is finally taking on the role of his older brother, Sam, whom he admires. However, the trip quickly becomes dangerous. He and his father are stopped by cowboys. The cowboys are angry because they believe that Mr. Meeker is selling Cattle to Loyalists. These cowboys claim to be Patriots, however, some believe that this claim is just a guise that masks their one true goal: thievery. Mr. Meeker argues that he does not care where it goes. He is just trying to support his family. This is one of several examples of Mr. Meeker's stubborn bravery, which resembles his son Sam's attitude.
The cowboys violently knock Mr. Meeker to the ground. Tim prepares to run for help. This is a crucial moment in which he tries to decide what the "right" thing to do would be. He struggles between the idea of running to Father's rescue, as he believes Sam would do, and which he believes would be courageous, and the idea of running for help, which he believes is the logical idea that his father would support. Before Tim runs for help, help comes to them. A group of Loyalist men who act as an escort scare the cowboys away and safely guide Mr. Meeker and Tim to Tim's cousins' home.
I disagree with you Mrs. English sorry but I read the book two times and I believe that the Cowboys ( Cattle Thieves) thought that Mr. meeker was selling Cattle (beef) to the the British.