<span>it weakened the soviet economy and encouraged mikhail gorbachev to promote reform in teh soviet union </span>
Answer: Germans: More than 1.5 million between 1820 and 1860. The 1850s was the single biggest decade for German immigration, with some 951,000 reaching the United States. Why They Came Irish: Most emigrated to escape grinding poverty in Ireland—or to avoid outright starvation in the years of the potato famine.
Explanation:
the answer to your question is a) they had advanced planning and developed effective military methods.
