 He was made secretary general of the ANC in 1949, displacing the more passive older leadership, and held that post until 1954.
<clarity>  He was made secretary general of the ANC in 1949, displacing the more passive older leadership, and held that post until 1954.
 He was made secretary general of the ANC in 1949, displacing the more passive older leadership, in a post he held until 1954.