As quoted by Lyman Abbott, in The Outlook (27 February 1909); repeated in the New York Times (6 March 1909); "Bully" in this sense was common slang adjective for "admirable", "excellent".
1900s, Bully Pulpit (1909)

“We shall make mistakes; and if we let these mistakes frighten us from our work we shall show ourselves weaklings.”

Theodore Roosevelt

1900s, The Strenuous Life: Essays and Addresses (1900), National Duties

“The process has aroused much antagonism, a great part of which is wholly without warrant. It is not true that as the rich have grown richer the poor have grown poorer. On the contrary, never before has the average man, the wage-worker, the farmer, the small trader, been so well off as in this country and at the present time. There have been abuses connected with the accumulation of wealth; yet it remains true that a fortune accumulated in legitimate business can be accumulated by the person specially benefited only on condition of conferring immense incidental benefits upon others. Successful enterprise, of the type which benefits all mankind, can only exist if the conditions are such as to offer great prizes as the rewards of success.”

Theodore Roosevelt

1900s, First Annual Message to Congress (1901)

“Poverty is a bitter thing; but it is not as bitter as the existence of restless vacuity and physical, moral, and intellectual flabbiness, to which those doom themselves who elect to spend all their years in that vainest of all vain pursuits—the pursuit of mere pleasure as a sufficient end in itself.”

Theodore Roosevelt

1900s, The Strenuous Life: Essays and Addresses (1900), National Duties

“Let me, in closing, put my position in a nutshell. When I say that I am for the square deal, I mean not merely that I stand for fair play under the present rules of the game, but that I stand for having these rules changed so as to work for a more substantial equality of opportunity and of reward for equally good service. So far as possible, the reward should be based upon service; and this necessarily implies that where a man renders us service in return for the fortune he receives, he has the right to receive it only on terms just to the whole people.”

Theodore Roosevelt

1910s, The Progressives, Past and Present (1910)

“It cannot be too often repeated that in this country, in the long run, we all of us tend to go up or go down together. If the average of well-being is high, it means that the average wage-worker, the average farmer, and the average business man are all alike well-off. If the average shrinks, there is not one of these classes which will not feel the shrinkage. Of course, there are always some men who are not affected by good times, just as there are some men who are not affected by bad times. But speaking broadly, it is true that if prosperity comes, all of us tend to share more or less therein, and that if adversity comes each of us, to a greater or less extent, feels the tension.”

Theodore Roosevelt

1900s, A Square Deal (1903)

“The growth of cities has gone on beyond comparison faster than the growth of the country, and the upbuilding of the great industrial centers has meant a startling increase, not merely in the aggregate of wealth, but in the number of very large individual, and especially of very large corporate, fortunes. The creation of these great corporate fortunes has not been due to the tariff nor to any other governmental action, but to natural causes in the business world, operating in other countries as they operate in our own.”

Theodore Roosevelt

1900s, First Annual Message to Congress (1901)

“To borrow a simile from the football field, we believe that men must play fair, but that there must be no shirking, and that the success can only come to the player who hits the line hard.”

Theodore Roosevelt

Sagamore Hill, Oyster Bay, NY http://www.trsite.org/content/pages/speaking-loudly (October 1897) <br class="br">1890s

“Our country—this great republic—means nothing unless it means the triumph of a real democracy, the triumph of popular government, and, in the long run, of an economic system under which each man shall be guaranteed the opportunity to show the best that there is in him.”

Theodore Roosevelt

1910s, The New Nationalism (1910)

“Corporations are necessary to the effective use of the forces of production and commerce under modern conditions. We cannot effectively prohibit all combinations without doing far-reaching economic harm; and it is mere folly to do as we have done in the past—to try to combine incompatible systems—that is, to try both to prohibit and regulate combinations. Combinations in industry are the result of an imperative economic law which cannot be repealed by political legislation. The effort at prohibiting all combination has substantially failed. The only course left is active corporate regulation – that is, the control of corporations for the common good—the suppression of the evils that they work, and the retention, as far as maybe, of that business efficiency in their use which has placed us in the forefront of industrial peoples.”

Theodore Roosevelt

1910s, The Progressives, Past and Present (1910)

“It is a bad thing for a nation to raise and to admire a false standard of success; and there can be no falser standard than that set by the deification of material well-being in and for itself.”

Theodore Roosevelt

1910s, Citizenship in a Republic (1910)

“Nevertheless, the fact that there are dangers in following a given course merely means that we should follow it with a cautious realization of these dangers, and not that we should abandon it, if on the whole it is the right course.”

Theodore Roosevelt

1910s, The Progressives, Past and Present (1910)

“As it is with the soldier, so it is with the civilian. To win success in the business world, to become a first-class mechanic, a successful farmer, an able lawyer or doctor, means that the man has devoted his best energy and power through long years to the achievement of his ends. So it is in the life of the family, upon which in the last analysis the whole welfare of the nation rests. The man or woman who, as bread-winner and home-maker, or as wife and mother, has done all that he or she can do, patiently and uncomplainingly, is to be honored; and is to be envied by all those who have never had the good fortune to feel the need and duty of doing such work.”

Theodore Roosevelt

1900s, A Square Deal (1903)

“If a man does not have an ideal and try to live up to it, then he becomes a mean, base, and sordid creature, no matter how successful.”

Theodore Roosevelt

Letter to his son, Kermit, quoted in Theodore Roosevelt by Joseph Bucklin Bishop http://www.trsite.org/content/pages/speaking-loudly (1915) <br class="br">1910s