Why did the founding fathers create an amendment process for the constitution?

What is walt whitman's poem "when i heard the learn'd astronomer about?

When conducting research for forming a hypothesis, which practice should historians follow?

Which source would best a historian understand the effect of the great chicago fire on families? a. a biography of a chicago family displaced by the fire b. a letter from a grandmother in new york to her family in chicago c. a newspaper editorial about families who were displaced d. an oral history dictated by an adolescent who fled the fire