Here are the statutory definitions of "lawyer" as indicated by the Index to the Federal Statutes.

Statutes-At-Large, THIRTY-SEVENTH CONGRESS, Session II, CH. 119, p.459:31, 1862:

"An Act to provide Internal Revenue to support the Government, to pay Interest on the Public Debt".

31. Lawyers shall pay ten dollars for each license. Every person whose business it is, for fee or reward, to prosecute or defend causes in any court of record or other judicial tribunal of the United States or of any of the States, or give advice in relation to causes or matters pending therein, shall be deemed to be a lawyer within the meaning of this act.

Statutes-At-Large, THIRTY-EIGHTH CONGRESS, Session I, CH. 173, p. 256:Forty-three, 1864:

"An Act to provide Internal Revenue to support the Government, to pay Interest on the Public Debt, and for other purposes".

Forty-three. Lawyers shall pay ten dollars for each license. Every person who, for fee or reward, shall prosecute or defend causes in any court of record or other judicial tribunal of the United States, or of any of the states, or give legal advice in relation to any cause or matter whatever, shall be deemed a lawyer within the meaning of this act.

Statutes-At-Large, THIRTY-NINTH CONGRESS, Session I, CH. 184, p. 121:Forty-three, 1866:

"An Act to reduce Internal Taxation and to amend an Act entitled "An Act to provide Internal Revenue to support the Government, to pay Interest on the Public Debt, and for other purposes", approved June thirtieth, eighteen hundred and sixty-four, and Acts amendatory thereof."

Forty-three. Lawyers shall pay ten dollars. Every person who for fee or reward shall prosecute or defend causes in court of record or other judicial tribunal of the United States or of any of the States, or whose business it is to give legal advice in relation to any cause or matter whatever, shall be deemed to be a lawyer.