TD's original brokerage was from the purchase of Gardiner Group Stockbrokers, which was renamed Greenline.
The brand originated as a United States brand for discount brokerage when TD purchased Waterhouse Securities. The name TD Waterhouse was formed and was used for TD's British, Canadian and U.S. brokerage activities. In Canada, TD Waterhouse thus replaced the brand Greenline.
In June 1999, TD spun off 42 million shares or 12.4% of TD Waterhouse in an IPO, with shares priced at $35.28 CAD or $24 USD per share, earning $1.01 billion USD. In 2001, with the bursting of the Dot-com bubble and lower trade volumes that brought down Waterhouse's share price, TD bought back that minority stake at $9 USD per share for only $378 million USD, earning a tidy profit on the privatization. The acquisition was conditional on TD owning at least 90 percent of Waterhouse's outstanding common shares, and it owned almost 89 percent when the privatization was announced.  
In 2003, the Toronto-Dominion Bank held talks to merge Waterhouse with E*TRADE, which would have created the second-largest discount broker in the US after Charles Schwab, but the two sides could not come to an agreement over control of the merged entity.
In 2005, E*TRADE made an unsolicited offer for Ameritrade, currently the second largest US discount broker. However, Ameritrade instead purchased TD Waterhouse USA, with TD Bank holding a 39% stake in the new entity. As part of the deal, Ameritrade sold its Canadian operations to TD Bank who merged them with TD Waterhouse Canada. TDBFG's Waterhouse and Ameritrade holdings, along with TD Mutual Funds, are now organized under a division known as TD Wealth.
When TD merged its U.S. brokerage activities with Ameritrade, the newly formed U.S. broker formed the brand TD Ameritrade (of which TD owns 39%), but the Canadian division (which are 100% owned by TD) retained the TD Waterhouse brand.
The Chairman and Chief Executive Officer of TD Wealth Management was Bill Hatanaka, a former Royal Bank of Canada executive. Before beginning his career in financial services, Hatanaka was educated at York University and played the position of running back for the Ottawa Rough Riders. Mike Pederson is the current Group Head for Wealth Management, Insurance, and Corporate Shared Services.