求翻译：惠特曼从1839年起开始文学创作，写一些短诗，同时参加当地的政治活动。1842年他担任《纽约曙光》报的编辑。1846年初，他又担任《布洛克林每日鹰报》的编辑，因在该报发表反对奴隶制度的文章，于1848年1月被解职。后来还担任过《自由民》报的主编，终因政见不合而于1840年离开新闻界。是什么意思？

Whitman began his literary creation since 1839, to write short poems, and participate in local political activities. In 1842, he served as editor of the New York Dawn newspaper. In early 1846, he served as the editor of the the Buloh Brooklyn Daily Eagle, "published in the newspaper article against