The plan made it so that each state got only one vote in congress. Instead of a different amount of votes depending on population. This helped smaller states because they wouldn't be overshadowed by bigger states.
Since New Jersey was a small state, they believed that there should have been one house in congress. Each state would have the same number of representatives regardless of the population. When Roger Sherman created the great compromise he considered the thoughts from the New Jersey plan and created a senate where each state had an equal amount of senator representation.
