Wachuku was co-founder and original shareholder, with Nnamdi Azikiwe, of the African Continental Bank (ACB), and first regional director of the bank, from 1948 to 1952. As ACB Director, he facilitated the opening of branches in Aba, Calabar, Port Harcourt and Enugu. Wachuku started his political career from the grassroots. In 1948, he was first nominated village councillor and later to the Nsulu Group Council. From 1949 to 1952, he was a Member of the Ngwa Native Authority, Okpuala Ngwa. In 1951, he entered regional politics and was elected Second Member for Aba Division in the Eastern Nigeria House of Assembly. From 1952 to 1953, Wachuku was elected Deputy Leader of the NCNC and Chairman of the Parliamentary Party when there was crisis in Nigeria's Eastern Region – resulting in the dissolution of the Eastern House of Assembly. Also, from 1952 to 1953, he was Chairman of the Eastern Regional Scholarship Board and Member of the Finance Committee in the House of Representatives of Nigeria. Wachuku went to the 1953 Constitutional Conference in London as Alternate Delegate and Adviser to the Nigerian Independence Party (NIP) – a break-away faction that was formed following the NCNC crisis of 1953.