21. Once in office, Jefferson extended slavery with the Louisiana Purchase in 1803 ; the new land was carved into 13 states, including three slave states.

【分析】并列句。分号将两个并列的简单句隔开。在前一个分句中,once in office为条件状语；后一分句中，including…作伴随状语。

【译文】登上总统宝座以后，杰弗逊在1803年通过购买 路易斯安那州扩大了奴隶制的存在范围。这片新的国土也被划分为13个州，其中包括三个实行奴隶制的州。

【点拨】carve into本义为“雕刻成”，在本句中意为“分割成”。

22. Washington, who had begun to believe that all men were created equal after observing the bravery of the black soldiers during the Revolutionary War, overcame the strong opposition of his relatives to grant his slaves their freedom in his will.

【分析】复合句。主句主干为Washington overcame the strong opposition。who引导的非限定性定语从句修饰Washington，其中that引导的从句作如believe的宾语，after... the Revolutionary War为时间状语。句尾的不定式结构to grant…作overcame的目的状语。

【译文】在独立战争期间，华盛顿目睹了黑人士兵的英勇，他开始相信人人生而平等。于是他不顾亲友的强烈反对，把赋予奴隶自由的决定写进了遗书。

【点拨】1)overcome意为“战胜，克服”，常用的搭配有overcome difficulty/adversity 战胜困难/困境；overcome dread 克服恐惧；overcome troubles 踏平坎坷。2)grant sb. sth.意为“授予某人某物”。