Shortly after hanging out his shingle, two individuals joined Kenneth McGuiness and became the core of the new organization—NLRB attorney Robert E. Williams and McGuiness' son, Jeffrey C. McGuiness. In the coming decades, McGuiness & Williams and its related entities would grow to more than 35 people providing services in the labor and employment field that included litigation, regulatory compliance, labor relations strategy, government representation and association management.  

From the mid-1970's through the 1980's, there was a broadening of the focus of senior industrial relations vice presidents beyond labor relations and policy along two lines. First, they turned their attention increasingly to compliance issues arising from the many employment, anti-discrimination and benefit laws enacted during the Johnson, Nixon and Carter years. It was during this time that Daniel V. Yager, a senior labor and employment counsel for the House Labor Committee, joined the firm after playing a key roles in the drafting of several of these new statutes. Other personnel changes were also underway within the firm itself. In 1988 at the age of 72, Kenneth McGuiness retired and Jeffrey McGuiness, now Senior Partner, was elected President of LPA, beginning the concept's second generation

A significant part of that compliance focus included affirmative action and discrimination issues in the workplace context. These issues first became prominent in the 1970s with the issuance of Executive Order 11246 and eventually gave rise to the Civil Rights Act of 1991 and an additional set of legal obligations.  In response, the firm's services were broadened to include a major affirmative action policy and regulatory practice directed at large employers, most of whom were also government contractors. By the mid-1990s, this practice area had rapidly grown to the extent that Jeffrey A. Norris was added as a name partner of the firm and represented the largest practice area.

The 1990s also saw the emergence of a new form of labor relations activity—the corporate campaign. In addition to traditional picketing and strike tactics, unions seek to gain leverage with employers using sophisticated economic, psychological, legal, regulatory and political attacks. Corporate campaign defense work requires an effective combination of legal, communications, and consulting skills, and the firm's labor relations practice was broadened accordingly.