The answer is "Union forces staged a surprise attack but were forced to retreat".
The Colombian exchange had a huge impact on the movement of people around the world. It opened the gates to two new continents. The indigenous people saw an invasion by people from Europe at first, people from other race and culture. The Europeans later started to bring in Africans on these two continents as well. As the time was passing, more and more people, from more and more countries and continents wanted to migrate toward these parts of the world. As those societies became more open toward migration, there was an influx of multiple different European ethnic groups, multiple different African ethnic groups, and in lesser degree East Asian people as well. All that movement of different people, from different ethnic groups, races, cultures, created societies were people from all over the world live together, work together, prosper together.
One of the main ways in which machines changed workers’ lives was that "<span>They divided labor into many small tasks," since this brought about a "specialization in labor," which caused production to be more efficient. </span>