Root joins CoverMyMeds as Central Ohio's billion-dollar "unicorns." The prescription management software company was acquired by McKesson Corp. last year for $1.3 billion. No other tech firm has raised so much venture capital in the region since SubmitOrder's cumulative $400 million in the 1990s.Also participating in this round are previous investors Redpoint Ventures, Ribbit Capital and Scale Venture Partners, all of which are based in the San Francisco and Silicon Valley region. Past investors also include Silicon Valley Bank Capital Partners and Columbus-based Drive Capital LLC, the first to invest three years ago.