GMAT Reading Comprehension (RC) | Re: The new school of political history that emerged in the 1960

Can someone pls explain me "Like the old approach, however, this new approach excluded women' .. I am not that great in grammer or language..so only thing i could understand was - 'new approach is similar to old approach'... What role does this word 'however' play here...I saw this word being used in the same fashion in a sentence in some other RC's also.

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