In William Bradford's Of Plymouth Plantation, the line "O after long beating at sea they fell with that land which is called Cape Cod; the which being made and certainly known to be were not a little joyful" most clearly shows his bias. This line indicates Bradford's positive and celebratory attitude towards reaching Cape Cod. The use of words like "joyful" and the tone of excitement reveal his personal perspective and feelings about the event.
Another line that demonstrates his bias is "were not a little joyful." This phrase explicitly conveys Bradford's emotional response to the situation, emphasizing his happiness and satisfaction upon reaching Cape Cod.
Overall, these lines reflect Bradford's subjective viewpoint and his tendency to interpret events in a way that aligns with his own emotions and beliefs.