long, long years of pain
McKay would leave his home of Jamaica, and would go from the United States all the way to Britain before this poem was published, which might contribute to the “long, long years”. During his time in America, he had face the harsh realities of racism, which could’ve been a factor in the “pain”, but the pain could very well have been something going on inside McKay’s head when he wrote this. The pain may also simply be a result of homesickness. http://www.english.illinois.edu/Maps/poets/m_r/mckay/life.htm