In 2007 and 2008, what happened for only the second time in u. s. history?

in february 1787, congress decided that a convention should be convened to revise the articles of confederation, the nation’s first constitution. in may, 55 delegates came to philadelphia, and the constitutional convention began. debates erupted over representation in congress, over slavery, and over the new executive branch. the debates continued through four hot and muggy months. but eventually the delegates reached compromises, and on september 17, they produced the u.s. constitution, replacing the articles with the governing document that has functioned effectively for more than 200 years.

first industrial revolution - the first wave of the industrial revolution lasted from the late 1700s to the mid-1800s. it industrialized the manufacture of textiles and began the move of production from homes to factories. steam power and the cotton gin played an important role in this period.