Hinshaw & Culbertson is adding a 23-lawyer Chicago firm, Adler Murphy & McQuillen, pointing to shared bases in the city, complementary civil litigation defense practices and a desire to grow, the firms said Thursday.

The move is official on April 1 and creates a roughly 460-lawyer firm. Hinshaw chairman Peter Sullivan said in an interview that he couldn’t say off-hand how much revenue Adler Murphy is adding, but he said the firms had been in discussions for over a year and a half and that the union bolsters its bench of trial lawyers while adding a specialty in aviation and aerospace litigation.